Segmented Backlight for Dynamic Contrast

ABSTRACT

Systems and methods for increasing dynamic contrast in a liquid crystal display (LCD) may include a segmented backlight that may include one or more segments and one or more sets of light emitting diodes (LEDs). Each set of LEDs may be configured to illuminate a corresponding segment and each segment may include a notch(es) configured as a light barrier to reduce light leakage to non-adjacent segments. The notch(es) may be of variable length, depth, and width and may be three-dimensional, having a width the varies along the depth and length of the notch and a depth that varies along the width and length of the notch. In some embodiments, the notch(es) may be reflective, some degree of opaque, and/or blackened.

PRIORITY DATA

This application claims benefit of priority to U.S. ProvisionalApplication Ser. No. 62/447,291, titled “Segmented Backlight for DynamicContrast”, filed Jan. 17, 2017, by Thanh-Son Nguyen and Hsienhui Cheng,which is hereby incorporated by reference in its entirety as thoughfully and completely set forth herein.

TECHNICAL FIELD

This disclosure relates to the field of liquid crystal displays and moreparticularly to methods and systems for increasing dynamic contrast inlower voltage liquid crystal display applications.

DESCRIPTION OF THE RELATED ART

Three-dimensional (3D) displays (actually, simulated 3D, e.g., viastereoscopic display (SD) techniques) are increasingly utilized for avariety of applications, including, for example, remote viewing,videoconferencing, video collaboration, and so forth.

FIG. 1 illustrates a modern display chain, according to typical priorart embodiments, which includes the following components:

1. GPU—Graphics Processing Unit. This component resides on a personalcomputer, workstation, or functional equivalent, and outputs videolevels for each color or channel of a supported color model, e.g., foreach of three colors, typically Red (R), Green (G), and Blue (B), foreach pixel on the display. Each of these numbers is typically an 8-bitnumber, with a range of 0 to 255, although other ranges are possible.

2. Scaler—This component takes as input the video levels (e.g., for R,G, and B) for each pixel output from the GPU, and processes them invarious ways, before outputting (usually) modified video levels for RGB,usually in the same 8-bit range of 0-255. This component may also scalean image from the input resolution to a different, rendered resolutionsupported by the display.

3. Panel—This component is the display itself, typically a liquidcrystal display (LCD), though other displays are possible, and takes asinput the video levels (e.g., for R, G and B) output from the scaler foreach pixel, and converts the video levels to voltages, which are thendelivered to each pixel on the display. The panel itself may modify thevideo levels before converting them to voltages.

The video chain generally modifies the video levels in two ways,specifically gamma correction and overdrive. Note that the functionalitydescribed above is typically implemented in the scaler, but is sometimesimplemented at least partially in other devices or elements of the videochain, e.g., in the GPU or display device (panel).

Time Sequential Stereo Displays

Unlike a normal (i.e., monoscopic) display, in a stereo display, thereare two images for each video frame: right and left. The right imagemust be delivered to only an observer's right eye, and the left imagemust be delivered to only the observer's left eye. In a time sequentialstereo display, this separation of right and left images is performed intime, i.e., the left and right images are presented sequentially, andthus, contains some time-dependent element which separates these twoimages. There are two common architectures for stereo displays.

The first architecture uses a device called a polarization switch (PS),which may be a distinct (i.e., separate) or integrated LC device orother technology switch and which is placed in front of the LCD panel(or any other type of imaging panel, such as an OLED (organic lightemitting diode) panel, a plasma display, etc.) or any other pixelatedpanel display used in a time-sequential stereo imaging system.Specifically, the PS switch may be placed between the display panel andthe viewer, as shown in FIG. 2A. The purpose of the PS is to switch thelight transmitted from the display panel between two orthogonalpolarization states. For example, one of these states may behorizontally linearly polarized light (i.e., the light may be in ahorizontal linear polarization state), and the other may be verticallylinearly polarized light (i.e., the light may be in a vertical linearpolarization state); however, other options are possible (e.g., left andright circular polarization states, etc.). The key feature that allowsthe PS to deliver the correct image to the correct eye of the viewer(i.e., the left image to the left eye and the right image to the righteye) is that the two polarization states are orthogonal to each other.

This architecture allows achievement of the stereo effect shown in priorart FIG. 2B. As may be seen, the top portion of the figure shows the(display) panel switching between a left image and a right image.Synchronous with the panel switching, the PS is switching the lightbeing transmitted between a left state and a right state, as shown.These two states emit two corresponding orthogonal polarization states,as explained above. As FIG. 2B further shows, the system includesstereoscopic eyewear that is designed such that the left lens will onlypass the left state polarization and the right lens will only pass theright state polarization. In this way, separation of the right and leftimages is achieved.

The second conventional architecture uses stereoscopic shutter glasses,which replace (or integrate the functionality of) the PS and eyewear. Insuch systems, each eye is covered by an optical shutter, which can beeither open or closed. Each of these shutters is cycled between openedand closed synchronously with the display panel in such a way that whenthe left image is shown on the display, only the left eye shutter isopen, and when the right image is shown on the display, only the righteye shutter is open. In this manner, the left and right views arealternatingly presented to the user's left and right eye, respectively.The alternate presentation of left and right views to the user's leftand right eyes creates the perception of visual depth, as shown in FIG.4. Virtual objects may be displayed in this created 3D space, whichexists both above the 3D stereoscopic display panel (i.e., negativespace) and below the stereoscopic display panel (i.e., positive space).

Liquid Crystal Displays (LCDs)

Some of the advantages of a liquid crystal display (LCD) include lighterweight, lower power consumption, and less radiation contamination. LCDmonitors have been widely applied to various portable informationproducts (e.g., user equipment devices such as laptops, tablets, mobilephones, PDAs, and so forth). Typically, in an LCD monitor, incidentlight produces different polarization or refraction effects when thealignment of liquid crystal molecules is altered. The liquid crystalmolecules affect the transmission of the incident light, and thus amagnitude of the light emitted from the liquid crystal molecules varies.The LCD monitor utilizes the characteristics of the liquid crystalmolecules to control the corresponding light transmittance and producesimages per different magnitudes of red, blue, and green light.

A schematic image of a nematic liquid crystalline phase 1000 is shown inFIG. 2C. The liquid crystal materials have no positional long-rangeordering of their molecules' centers of mass, as in crystals. However,the liquid crystal materials possess long-range orientational orderingof their molecules along a main axis direction (in the simplest case ofso-called nematic liquid crystal), effectively allowing the molecules tobe aligned along one preferred direction, called the director of theliquid crystal, {right arrow over (n)} (see FIG. 2C).

Liquid crystal molecules either possess a permanent dipole moment, oracquire the induced dipole moment when placed in an electric field. Inboth cases, in the electric field a liquid crystal molecule 2000 ischaracterized by some dipole moment, μ. This dipole may be aligned alongthe molecule's symmetry axis (such materials are said to have thepositive dielectric anisotropy) or perpendicular to it (the negativedielectric anisotropy). The separation of charge in a molecule leads toits rotation in the electric field until it is aligned parallel orperpendicular to the applied field, depending on a sign of thematerial's dielectric anisotropy. FIG. 2D depicts such re-orientation ofa liquid crystal molecule with the positive dielectric anisotropy.

As all of the molecules in the liquid crystalline phase are subject tothe re-orientation under the effect of the electric field at the sametime, it is possible to control the symmetry axis of the phase (thedirector) and usually the optical axis of the liquid crystalline sample.

FIG. 2E illustrates the configuration of liquid crystal molecules 300within a conventional twisted nematic liquid crystal based polarizationrotator. The nematic liquid crystal is chosen to have a positivedielectric anisotropy. The left-hand side of the figure illustrates thevoltage OFF, 90-degree rotation state. The right-hand side of the figureillustrates the voltage ON, 0-degree rotation state.

Depending on the type of the liquid crystal cell and the relativeorientations of the liquid crystal cell's optical axis and thepolarizers' transmission axis, the polarization rotator can operate ineither Normal White (NW) or Normal Black (NB) mode. These modes aregoverned by the optical transmission in the zero or low-voltage state,i.e. the Normal White mode corresponds to the maximum opticaltransmission in the zero or low-voltage state, and the minimumtransmission in the high-voltage state; it is the opposite for theNormal Black mode.

The twisted nematic polarization rotator usually operates in the NormalWhite mode. In this case the higher applied voltage improves thecontrast ratio of the Normal White mode due to the decrease of theresidual retardation of a liquid crystal cell.

Other type of polarization rotators such as electrically controlledbirefringence (ECB) mode can operate both in Normal White and NormalBlack modes. Using additional optical elements in the 3D system (such astwo orthogonal polarizers), the same polarization rotator can operate inthe both modes alternately in each every frame.

SUMMARY

Various embodiments of a system for implementing methods for increasingdynamic contrast in a liquid crystal display (LCD). In some embodiments,an LCD may include a segmented backlight. The segmented backlight mayinclude one or more segments and one or more sets of light emittingdiodes (LEDs) configured to illuminate the segmented backlight. Each setof LEDs may illuminate a corresponding segment of the one or moresegments. Each segment of the one or more segments may include one ormore notches (or cuts) and each notch of the one or more notches may beconfigured as a light barrier that may reduce light leakage tonon-adjacent segments. In some embodiments, the one or more notches, ora subset thereof, may be of variable length, depth, and width. In someembodiments, the one or more notches, or a subset thereof, may bearranged to be perpendicular to the one or more sets of LEDs. In someembodiments, the one or more notches, or a subset thereof, may bethree-dimensional, having a width the varies along the depth and lengthof the notch and a depth that varies along the width and length of thenotch. In some embodiments, the one or more notches, or a subsetthereof, may be non-linear in a direction perpendicular to the one ormore sets of LEDs. In some embodiments, the one or more notches, or asubset thereof, may be reflective (e.g., reflect all light), some degreeof opaque (e.g., absorb a portion of light, such as 10%, 20%, 30%, 40%,and so forth up to 99%), or blackened (e.g., darkened to absorbsubstantially all light). In some embodiments, the LCD may be includedin any of a user equipment device, including a wireless phone, table,and/or laptop, a head mounted display device, a desktop computer, and/orany other type of display device. In some embodiments, the LCD may beincluded in a three-dimensional stereoscopic display system. In someembodiments, the three-dimensional stereoscopic display system may beany of a user equipment device, including a wireless phone, table,and/or laptop, a head mounted display device, a desktop computer, and/orany other type of display device.

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of the present disclosure can be obtained whenthe following detailed description of the preferred embodiment isconsidered in conjunction with the following drawings, in which:

FIG. 1 illustrates a modern display chain, according to implementations.

FIG. 2A illustrates an example of an architecture that utilizes apolarization switch, according to implementations.

FIG. 2B illustrates an example of a stereo effect (simulated 3D) usingpolarization switching between left and right views, according toimplementations.

FIG. 2C illustrates an example of a schematic diagram of a nematicliquid crystalline phase, according to implementations.

FIG. 2D illustrates an example of a schematic diagram of a switching ofa liquid crystal molecule in an electric field, according toimplementations.

FIG. 2E illustrates an example of a schematic diagram of a configurationof liquid crystal molecules within a conventional twisted nematic liquidcrystal based polarization rotator, according to implementations.

FIGS. 3A and 3B illustrate examples of 3D stereoscopic display systemsconfigured according to some embodiments.

FIG. 4 illustrates an example block diagram of a user equipment deviceconfigured according to some embodiments.

FIGS. 5A and 5B illustrate examples of a 3D head-mounted stereoscopicdisplay system configured according to some embodiments.

FIG. 5C illustrates an example block diagram of a head-mountedelectronic device configured according to some embodiments.

FIG. 6 illustrates an example of a user input device, according to someembodiments.

FIG. 7A illustrates example liquid crystal display systems, according tosome embodiments.

FIG. 7B illustrates an example block diagram of a liquid crystal displaysystem, according to some embodiments.

FIG. 8 is an example of a block diagram of a liquid crystal displaysystem, according to some embodiments.

FIG. 9 illustrates an optical response of a liquid crystal cell underconsecutive switching between low and high voltage states, according toexisting implementations.

FIG. 10 illustrates a segmented pulsing backlight and voltage level ofan LCD, according to existing implementations.

FIG. 11 illustrates an example of a segmented backlight, according tosome embodiments.

FIGS. 12A-C illustrate an example of a notch in a segmented backlight,according to some embodiments.

FIGS. 13A-C illustrate another example of a notch in a segmentedbacklight, according to some embodiments.

FIGS. 14A-C illustrate a further example of a notch in a segmentedbacklight, according to some embodiments.

FIGS. 15A-C illustrate another further example of a notch in a segmentedbacklight, according to some embodiments.

While the disclosure is susceptible to various modifications andalternative forms, specific embodiments thereof are shown by way ofexample in the drawings and are herein described in detail. It should beunderstood, however, that the drawings and detailed description theretoare not intended to limit the disclosure to the particular formdisclosed, but on the contrary, the intention is to cover allmodifications, equivalents and alternatives falling within the spiritand scope of the present disclosure as defined by the appended claims.

DETAILED DESCRIPTION Terms

The following is a glossary of terms used in the present application:

Memory Medium—any of various types of memory devices or storage devices.The term “memory medium” is intended to include an installation medium,e.g., a CD-ROM, floppy disks, or tape device; a computer system memoryor random access memory such as DRAM, DDR RAM, SRAM, EDO RAM, RambusRAM, EEPROM, etc.; a non-volatile memory such as a Flash, magneticmedia, e.g., a hard drive, or optical storage; registers, or othersimilar types of memory elements, etc. The memory medium may compriseother types of memory as well or combinations thereof. In addition, thememory medium may be located in a first computer in which the programsare executed, or may be located in a second different computer whichconnects to the first computer over a network, such as the Internet. Inthe latter instance, the second computer may provide programinstructions to the first computer for execution. The term “memorymedium” may include two or more memory mediums which may reside indifferent locations, e.g., in different computers that are connectedover a network.

Carrier Medium—a memory medium as described above, as well as a physicaltransmission medium, such as a bus, network, and/or other physicaltransmission medium that conveys signals such as electrical,electromagnetic, or digital signals.

Computer System—any of various types of computing or processing systems,including a personal computer system (PC), mainframe computer system,workstation, network appliance, Internet appliance, personal digitalassistant (PDA), smart phone, television system, grid computing system,tablet, or other device or combinations of devices. In general, the term“computer system” can be broadly defined to encompass any device (orcombination of devices) having at least one processor that executesinstructions from a memory medium.

Graphical Processing Unit—refers to a component that may reside on apersonal computer, workstation, server, graphics server, or equivalent,and outputs video levels for each color or channel of a supported colormodel, e.g., for each of three colors, typically Red (R), Green (G), andBlue (B), for each pixel on the display. Each of these numbers istypically an 8 bit number, with a range of 0 to 255, although otherranges are possible.

Mobile Device (or Mobile Station)—any of various types of computersystems devices which are mobile or portable and which performs wirelesscommunications using WLAN communication. Examples of mobile devicesinclude mobile telephones or smart phones (e.g., iPhone™, Android™-basedphones), and tablet computers such as iPad™ Samsung Galaxy™, etc.Various other types of devices would fall into this category if theyinclude Wi-Fi or both cellular and Wi-Fi communication capabilities,such as laptop computers (e.g., MacBook™), portable gaming devices(e.g., Nintendo DS™, PlayStation Portable™, Gameboy Advance™, iPhone™),portable Internet devices, and other handheld devices, as well aswearable devices such as smart watches, smart glasses, headphones,pendants, earpieces, etc. In general, the term “mobile device” can bebroadly defined to encompass any electronic, computing, and/ortelecommunications device (or combination of devices) which is easilytransported by a user and capable of wireless communication using WLANor Wi-Fi.

Wireless Device (or Wireless Station)—any of various types of computersystems devices which performs wireless communications using WLANcommunications. As used herein, the term “wireless device” may refer toa mobile device, as defined above, or to a stationary device, such as astationary wireless client or a wireless base station. For example awireless device may be any type of wireless station of an 802.11 system,such as an access point (AP) or a client station (STA or UE). Furtherexamples include televisions, media players (e.g., AppleTV™, Roku™,Amazon FireTV™, Google Chromecast™, etc.), refrigerators, laundrymachines, thermostats, and so forth.

WLAN—The term “WLAN” has the full breadth of its ordinary meaning, andat least includes a wireless communication network or RAT that isserviced by WLAN access points and which provides connectivity throughthese access points to the Internet. Most modern WLANs are based on IEEE802.11 standards and are marketed under the name “Wi-Fi”. A WLAN networkis different from a cellular network.

Processing Element (or Functional Unit)—refers to variousimplementations of digital circuitry that perform a function in acomputer system. Additionally, processing element may refer to variousimplementations of analog or mixed-signal (combination of analog anddigital) circuitry that perform a function (or functions) in a computeror computer system. Processing elements include, for example, circuitssuch as an integrated circuit (IC), ASIC (Application SpecificIntegrated Circuit), portions or circuits of individual processor cores,entire processor cores, individual processors, programmable hardwaredevices such as a field programmable gate array (FPGA), and/or largerportions of systems that include multiple processors.

Coupled Zone—refers to a physical volume in which the user of a 3Dstereoscopic display can view 3D content within the human eye's naturaldepth of field. As shown in FIG. 4, when a person sees an object in thephysical world, the person's eyes converge on, or look (individuallyaim) at, the object. Additionally, as the two eyes converge on theobject, each eye's lens also focuses, via accommodation,(monoscopically) on the object. In this sense, both eyes focus andconverge on the object, thus focus and convergence are “coupled.”

Disparity—refers to the difference between the left eye and right eyeimages of a 3D stereoscopic display. Disparity may be described in atleast two ways. First, with respect to the display device, i.e., the 3Dstereoscopic display, disparity may be described by the number of pixelsof separation between corresponding positions of the image, or content,being displayed, or rendered. In other words, the pixels of separationbetween the left eye and right eye images, or content. Alternatively, orin addition to, with respect to the point of view of the user, disparitymay be described by the degree of angular separation betweencorresponding positions in the images, or content, being displayed, orrendered, i.e., the angular separation between the left eye and righteye images, or content.

Projection—refers the display of a 3D object, or content, on atwo-dimensional (2D) display. Thus, a projection may be described as themathematical function applied to objects within a virtual 3D scene todetermine the virtual position of the objects within a 3D space that maybe defined by the size of the 3D stereoscopic display and the point ofview of a user.

Viewpoint—This term has the full extent of its ordinary meaning in thefield of computer graphics/cameras and specifies a location and/ororientation. For example, the term “viewpoint” may refer to a singlepoint of view (e.g., for a single eye) or a pair of points of view(e.g., for a pair of eyes). Thus, viewpoint may refer to the view from asingle eye, or may refer to the two points of view from a pair of eyes.A “single viewpoint” may specify that the viewpoint refers to only asingle point of view and a “paired viewpoint” or “stereoscopicviewpoint” may specify that the viewpoint refers to two points of view(and not one). Where the viewpoint is that of a user, this viewpoint maybe referred to as an eyepoint (see below) or “physical viewpoint”. Theterm “virtual viewpoint” refers to a viewpoint from within a virtualrepresentation or 3D scene. A viewpoint is synonymous with “point ofview” (POV). (See definition of POV below.)

Eyepoint—the physical location (and/or orientation) of a single eye or apair of eyes. A viewpoint above may correspond to the eyepoint of aperson. For example, a person's eyepoint has a corresponding viewpoint.

Point of View (POV)—refers to or specifies a position and orientation.For example, a POV may be a viewpoint or eyepoint, generally of a user,but may also be a viewpoint of an optical device, such as a camera. ThePOV is generally a means to capture a relationship between two or more 6degree of freedom objects. In a typical application of the presenttechniques, a user's pair of eyes or head (view) is positioned in any X,Y, Z position and/or pitch, yaw, roll orientation to a display device,e.g., a monitor screen, which may have its own position in any X, Y, Zposition and/or pitch, yaw, roll orientation. In this example, the POVcan be defined as the position/orientation of the user's view withrespect to the positioning/orientation of the display device. The POVdetermination may be identified by a capture system. In a typicalapplication of the present techniques, one or more tracking devices areattached to the display device, such that the controller knows what thetracking system tracks in the context of the display device, meaning thetracking system, being attached to the display device, isprogrammatically aware of the position/orientation of the displaydevice, as well as any potential change to the position/orientation ofthe display device.

The tracking system (which may identify and track, among other things,the user's view) may identify the position/orientation of the user'sview, and this information may then be correlated to the trackingsystem's identification of the viewing device's position/orientation(again, with respect to the display device).

Vertical Perspective—a perspective effect rendered from a viewpointwhich is substantially perpendicular to the display surface.“Substantially perpendicular” refers to 90 degrees or variationsthereof, such as 89 or 91 degrees, 85-95 degrees, or any variation whichdoes not cause noticeable distortion of the rendered scene. A verticalperspective may be a central perspective, e.g., having a single (andcentral) vanishing point. As used herein, a vertical perspective mayapply to a single image or a stereoscopic image. When used with respectto a stereoscopic image (e.g., presenting a stereoscopic image accordingto a vertical perspective), each image of the stereoscopic image may bepresented according to the vertical perspective, but with differingsingle viewpoints.

Horizontal or Oblique Perspective—a perspective effect rendered from aviewpoint which is not perpendicular to the display surface. Moreparticularly, the term “horizontal perspective” may typically refer to aperspective effect which is rendered using a substantially 45-degreeangled render plane in reference to the corresponding viewpoint. Therendering may be intended for a display which may be positionedhorizontally (e.g., parallel to a table surface or floor) in referenceto a standing viewpoint. “Substantially 45 degrees” may refer to 45degrees or variations thereof, such as 44 and 46 degrees, 40-50 degrees,or any variation which may cause minimal distortion of the renderedscene. As used herein, a horizontal perspective may apply to a singleimage or a stereoscopic image. When used with respect to a stereoscopicimage (e.g., presenting a stereoscopic image according to a horizontalperspective), each image of the stereoscopic image may be presentedaccording to the horizontal perspective, but with differing singleviewpoints.

Another conception of the horizontal perspective as commonly used inembodiments of the present techniques relates to the projection of theintended rendered graphics to the viewing device. With the POVdetermined, a horizontal perspective engine may identify the correctgraphics frustum in the 3D space, taking into account the position andorientation of the viewing device as defining the render plane of thefrustum and the user's view in position and orientation to define acamera point of the frustum in relation to the render plane. Theresultant projection is then rendered onto the viewing device as will beseen by the user.

Position—the location or coordinates of an object (either virtual orreal). For example, position may include x, y, and z (i.e., location)coordinates within a defined space. The position may be relative orabsolute, as desired. Position may also include yaw, pitch, and rollinformation, e.g., when defining the orientation of a viewpoint. Inother words, position is defined broadly so as to encompass informationregarding both location and orientation.

Stylus—a peripheral device or element such as a handheld device,handheld pen device, handheld pointing device, hand, finger, glove, orany object used to directly interact with rendered virtual objects as ina stereo rendered virtual projected objects.

Liquid Crystal Device—an electro-optical device that uses a liquidcrystal material to manipulate light by the application of a voltage.

Liquid Crystal Light Modulator—a liquid crystal device that manipulatesthe intensity of light passing through it. An example of a type ofliquid crystal light modulator is a liquid crystal display (LCD), whichmay be pixelated.

Polarization Switch (PS)—a liquid crystal device that manipulates thepolarization of light passing through it. Note that the PS does notgenerally change the intensity of light on its own. It may typically beaccomplished when the PS is used in conjunction with an analyzer. Ananalyzer may be a polarizer that is used to block or pass somepredetermined polarization state. For example, an LCD typically has apolarizer on the input side and a polarizer on the output side. Theoutput polarizer is called an analyzer. Eyewear may act as an analyzerin some embodiments.

PS Segment—a segment of a PS that is independently controllable.

Pixel—an individually addressable element of an LCD.

Liquid Crystal Cell or Liquid Crystal Layer—the layer of liquid crystalmaterial enclosed by the top and bottom substrates of an liquid crystaldevice.

Liquid Crystal Mode—the liquid crystal design used in a liquid crystaldevice. The design may include the specific type of liquid crystalmaterial, the thickness of the cell, the orientation of the alignmentdirections, etc. Typical liquid crystal modes include TN, VA (verticalalignment), IPS (In Plane Switching), etc.

Driven State—the term driven state may refer to a higher voltage stateof a liquid crystal (e.g., +/−2.5 V, +/−5 V, +/−10 V, +/−12 V, etc.). Asan example using a Twisted Nematic (TN) liquid crystal device, thedriven state of the +/−10 V may correspond to the position andorientation of the liquid crystal such that the liquid crystal rotatesthe polarization of polarized light entering the liquid crystal devicefrom the non-driven state in a manner that the polarization of theincoming light equals the polarization of the outgoing light.

Relaxed State—the term relaxed state may refer to the low voltage stateof a liquid crystal (e.g., 0 V). As an example using a TN liquid crystaldevice, the relaxed state of the liquid crystal may correspond to theposition and orientation of the liquid crystal liquid crystal such thatthe polarized light entering the liquid crystal rotates thepolarization.

Frame Time—the period that contains one driven state and one relaxedstate. The frame time may include two frames worth of data. For example,in a 3D system that alternates between left and right eye frames, aframe time may include one left eye frame and one right eye frame.

Normal White—corresponds to a white optical state at 0V. Thus, normalwhite corresponds to a normally high luminance state at 0V where lightis transmitted through a polarization switch (and liquid crystals). Oneexample of a normal white polarization switch includes 90° twistednematic liquid crystals. In context of an embodiment using thepolarization switch and corresponding eyewear, where the two lenses ofthe two eyepieces of the eyewear are cross polarized, normal white meansthat, at the relaxed state of the PS, the lens that is at samepolarization to the PS at the relaxed state is normally white (e.g.light passing through the PS is seen through normal white lens.)

Normal Black—corresponds to a black optical state at 0V. Thus, if novoltage is applied, light may not be transmitted through a polarizationswitch (and liquid crystals). A PS may be used in both a normal blackand normal white mode simultaneously. For example, in a 3D system thatalternates between left and right eye images, one eye may be the normalblack eye and the other may be the normal white eye. Eyewear (e.g.,passive eyewear or shutter glasses) may be used in conjunction with sucha system. In context of an embodiment using the polarization switch andcorresponding eyewear, where the two lenses of the two eyepieces of theeyewear are cross polarized, normal black means that, at the drivenstate of the PS, the lens that is at same polarization to the PS at thedriven state is normally black (i.e. light passing through the PS isseen through normal black lens.)

Optical Bounce—A temporary increase or decrease in the optical responseof a liquid crystal device due to backflow effect in certain liquidcrystal configurations. The optical bounce may appear as an oscillationin the transmission-time curve after an electric or magnetic field hasbeen removed from a liquid crystal cell. Therefore, optical bounce mayinclude a delay in reaching the relaxed state and an unintended opticaleffect as well. The optical effect may result in light leakage in thewhite normal state and a drop in luminance in the black normal state.

Similar—as used herein in reference to geometrical shapes, refers to thegeometrical term indicating that objects have the same shape, or thatone object has the same shape as the mirror image of the other object.In other words, objects are considered similar if one object may beobtained from the other by uniformly scaling (enlarging or shrinking)the object. Additionally, the term similar, or similar objects, meansthat either object may be rescaled, repositioned, and reflected, so asto coincide with the other object. Thus, for example, if a first objectis geometrically similar to a second object, i.e., has the same shapebut possibly a different size, then either object may be uniformlyscaled to obtain the geometrical size and shape of the other object.Thus, the first object may be uniformly scaled to obtain the secondobject or the second object may be uniformly scaled to obtain the firstobject. Note that this definition of similar only refers to the use ofthe word in the context of geometrical shapes and retains it ordinarymeaning in other contexts (e.g., system A is similar to system B impliesthat system A resembles system B without being identical to system B).

Approximately—refers to a value that is correct or exact within somespecified tolerance. For example, approximately may refer to a valuethat is within 1 to 10 percent of the exact (or desired) value. Itshould be noted, however, that the actual threshold value (or tolerance)may be application dependent. For example, in one embodiment,“approximately” may mean within 0.1% of some specified or desired value,while in various other embodiments, the threshold may be, for example,2%, 3%, 5%, and so forth, as desired or as required by the particularapplication.

Proximate—near to; for example, proximate may mean within some specifieddistance, or within some specified fraction of a distance. Note that theactual threshold for being proximate is generally application dependent.Thus, in various applications, proximate may mean being within 1 mm, 1inch, 1 foot, 1 meter, 1 mile, etc. of some reference point or object,or may refer to being within 1%, 2%, 5%, 10%, etc., of a referencedistance from some reference point or object.

Substantially—refers to a term of approximation. Similar to the term“approximately,” substantially is meant to refer to some tolerablerange. Thus, if part A is substantially horizontal, then part A may behorizontal (90 degrees from vertical), or may be within some tolerablelimit of horizontal. For example, in one application, a range of 89-91degrees from vertical may be tolerable, whereas, in another application,a range of 85-95 degrees from vertical may be tolerable. Further, it maybe that the tolerable limit is one-sided. Thus, using the example of“part A is substantially horizontal,” it may be tolerable for Part A tobe in a range of 60-90 degrees from vertical, but not greater than 90degrees from vertical. Alternatively, it may be tolerable for Part A tobe in a range of 90-120 degrees from vertical but not less than 90degrees from vertical. Thus, the tolerable limit, and therefore, theapproximation referenced by use of the term substantially may be asdesired or as required by the particular application.

Concurrent—refers to parallel execution or performance, where tasks,processes, or programs are performed in an at least partiallyoverlapping manner. For example, concurrency may be implemented using“strong” or strict parallelism, where tasks are performed (at leastpartially) in parallel on respective computational elements, or using“weak parallelism”, where the tasks are performed in an interleavedmanner, e.g., by time multiplexing of execution threads.

Automatically—refers to an action or operation performed by a computersystem (e.g., software executed by the computer system) or device (e.g.,circuitry, programmable hardware elements, ASICs, etc.), without userinput directly specifying or performing the action or operation. Thusthe term “automatically” is in contrast to an operation being manuallyperformed or specified by the user, where the user provides input todirectly perform the operation. An automatic procedure may be initiatedby input provided by the user, but the subsequent actions that areperformed “automatically” are not specified by the user, i.e., are notperformed “manually,” where the user specifies each action to perform.For example, a user filling out an electronic form by selecting eachfield and providing input specifying information (e.g., by typinginformation, selecting check boxes, radio selections, etc.) is fillingout the form manually, even though the computer system must update theform in response to the user actions. The form may be automaticallyfilled out by the computer system where the computer system (e.g.,software executing on the computer system) analyzes the fields of theform and fills in the form without any user input specifying the answersto the fields. As indicated above, the user may invoke the automaticfilling of the form, but is not involved in the actual filling of theform (e.g., the user is not manually specifying answers to fields butrather they are being automatically completed). The presentspecification provides various examples of operations beingautomatically performed in response to actions the user has taken.

Comprising—this term is open-ended, and means “including.””. As used inthe appended claims, this term does not foreclose additional elements,structure, or steps. Consider a claim that recites: “A system comprisinga display . . . ”; such a claim does not foreclose the system fromincluding additional components (e.g., a voltage source, a light source,etc.).

Configured To—various units, circuits, or other components may bedescribed or claimed as “configured to” perform a task or tasks. In suchcontexts, “configured to” is used to connote structure by indicatingthat the units/circuits/components include structure (e.g., circuitry)that performs those task or tasks during operation. As such, theunit/circuit/component can be said to be configured to perform the taskeven when the specified unit/circuit/component is not currentlyoperational (e.g., is not on). The units/circuits/components used withthe “configured to” language include hardware—for example, circuits,memory storing program instructions executable to implement theoperation, etc. Reciting that a unit/circuit/component is “configuredto” perform one or more tasks is expressly intended not to invoke 35U.S.C. § 112(f) for that unit/circuit/component. Additionally,“configured to” can include generic structure (e.g., generic circuitry)that is manipulated by software and/or firmware (e.g., an FPGA or ageneral-purpose processor executing software) to operate in manner thatis capable of performing the task(s) at issue.

First, Second, etc. —these terms are used as labels for nouns that theyprecede, and do not imply any type of ordering (e.g., spatial, temporal,logical, etc.). For example, in a system having multiple trackingsensors (e.g., cameras), the terms “first” and “second” sensors may beused to refer to any two sensors. In other words, the “first” and“second” sensors are not limited to logical sensors 0 and 1.

Based On—this term is used to describe one or more factors that affect adetermination. This term does not foreclose additional factors that mayaffect a determination. That is, a determination may be solely based onthose factors or based, at least in part, on those factors. Consider thephrase “determine A based on B.” While B may be a factor that affectsthe determination of A, such a phrase does not foreclose thedetermination of A from also being based on C. In other instances, A maybe determined based solely on B.

This specification may include references to “one embodiment” or “anembodiment.” The appearances of the phrases “in one embodiment” or “inan embodiment” do not necessarily refer to the same embodiment.Particular features, structures, or characteristics may be combined inany suitable manner consistent with this disclosure.

FIGS. 3-6 Exemplary Systems

FIGS. 3A and 3B illustrate exemplary systems configured to implementvarious embodiments of the techniques described below.

In the exemplary embodiment of FIG. 3A, computer system 100A may includechassis 110A, display 150A and display 150B (which may collectively bereferred to as display 150 or “one or more displays” 150), keyboard 120,mouse 125, user input device 130, eyewear 140, at least two cameras 160,and caddy 170. Note that in some embodiments, two displays 150A and 150Bmay not be used; instead, for example, a single display 150 may be used.In various embodiments, at least one of the displays 150A and 150B maybe a stereoscopic display. For example, in one embodiment, both of thedisplays 150A and 150B may be stereoscopic displays. Or, in otherembodiments, the single display 150 may be a stereoscopic display. It isnoted that a stereoscopic display may also be configured to displaytwo-dimensional (2D) objects and may be configured to operate in a 2Dmode.

The chassis 110A may include various computer components such asprocessors, at least one memory medium (e.g., RAM, ROM, hard drives,etc.), graphics circuitry, audio circuitry, and other circuitry forperforming computer tasks, such as those described herein. The at leastone memory medium may store one or more computer programs or softwarecomponents according to various embodiments of the present invention.For example, the memory medium may store one or more graphics engineswhich are executable to perform some of the techniques described herein.In certain embodiments, the graphics engine may be implemented on or bya functional unit or processing element. As used herein, and as noted inthe Terms section above, the term functional unit or processing elementrefers to any of various elements or combinations of elements configuredto process instructions and/or data. Processing elements include, forexample, circuits such as an ASIC (Application Specific IntegratedCircuit), portions or circuits of individual processor cores, entireprocessor cores, individual processors, programmable hardware devicessuch as a field programmable gate array (FPGA), and/or larger portionsof systems that include multiple processors, as well as any combinationsthereof.

The memory medium (which may include two or more memory mediums) mayalso store data (and/or program instructions) (e.g., implementing orspecifying a computer model) representing a virtual space, which may beused for projecting a 3D scene, such as scene 180, of the virtual spacevia the display(s) 150. Further, the memory medium may store softwarewhich is executable to perform three-dimensional spatial tracking (e.g.,user view tracking, user control tracking, etc.), content processing, orother features, as described herein. For example, the computer systemmay include a tracking system that may track one or more of a user'shead, a user's hand, or the stylus. Additionally, the memory medium maystore operating system software, as well as other software for operationof the computer system. Various embodiments further include receiving orstoring instructions and/or data implemented in accordance with theforegoing description upon a carrier medium.

As indicated above, the computer system 100A may be configured todisplay a three-dimensional (3D) scene (e.g., via stereoscopic images),or 3D content, such as scene 180, using the display 150A and/or thedisplay 150B. The computer system 100A may also be configured to displaya “view” of the 3D scene using the display 150A, the display 150B,and/or another display, as described in more detail below. The “view” ofthe 3D scene, or content, may refer to a displayed portion of the 3Dscene from a viewpoint within the 3D scene. A viewpoint within the 3Dscene may be referred to as a “virtual viewpoint.” The view may bestereoscopic, e.g., may be displayed on a stereoscopic display.Alternatively, the view may be monoscopic (not stereoscopic), and may bedisplayed on either a monoscopic display or a stereoscopic display. Notethat a monoscopic image or scene displayed on a stereoscopic display mayappear the same as on a monoscopic display system.

It should be noted that the embodiment of FIG. 3A is exemplary only, andother numbers of displays are also envisioned. For example, the computersystem 100A may include only a single display or more than two displays,or the displays may be arranged in different manners than shown, e.g.,as goggles or other wearable eyewear or headgear as further describedbelow in reference to FIG. 5. In this particular embodiment, the display150A is configured as a vertical display (which may be perpendicular orapproximately perpendicular to a user's line of sight) and the display150B is configured as a horizontal display (which may be parallel (orapproximately parallel) or oblique to a user's line of sight). Thevertical display 150A may be used (e.g., via instructions sent by agraphics engine executing in the chassis 110A) to provide images whichare presented according to a vertical (or central) perspective and thedisplay 150B may be used (e.g., via instructions sent by a graphicsengine executing in the chassis 110A) to provide images that arepresented according to a horizontal perspective. Descriptions ofhorizontal and vertical perspectives are provided herein (see, e.g., theabove Terms section). Additionally, while the displays 150 are shown asflat panel displays, in other embodiments, they may be any type ofdevice or system which is capable of displaying images, e.g., projectionsystems. For example, display(s) 150 may be or include a CRT (cathoderay tube) monitor, a LCD (liquid crystal display) monitor, or a frontprojection or a back projection screen or surface with a plurality ofprojectors, among others. Display(s) 150 may include a light emittingdiode (LED) backlight or other type of backlight.

Either or both of the displays 150A and 150B may present (display)stereoscopic images for viewing by the user. By presenting stereoscopicimages, the display(s) 150 may present a 3D scene for the user. This 3Dscene may be considered or referred to as an illusion or simulated 3Dbecause the actual provided images are 2D, but the scene is conveyed in3D via the user's interpretation of the provided images via stereoscopiceffects. In order to properly view the stereoscopic images (one for eacheye for each image frame), the user may wear eyewear 140. Eyewear 140may be any of anaglyph glasses, polarized glasses, shutter glasses,lenticular glasses, etc., among others. In some embodiments, thedisplay(s) 150 may be included (or incorporated) in the eyewear (orother wearable headgear). In embodiments using anaglyph glasses, imagesfor a first eye are presented according to a first color (and thecorresponding lens has a corresponding color filter) and images for asecond eye are projected according to a second color (and thecorresponding lens has a corresponding color filter). With polarizedglasses, images are presented for each eye using orthogonalpolarizations, and each lens of the eyewear has the correspondingorthogonal polarization for receiving the corresponding image. Withshutter glasses, each lens is synchronized with respect to left andright eye images provided by the display(s) 150, e.g., in alternatingfashion. The display may provide both polarizations simultaneously or inan alternating manner (e.g., sequentially), as desired. Thus, the lefteye may be allowed to only see left eye images during the left eye imagedisplay time and the right eye may be allowed to only see right eyeimages during the right eye image display time. With lenticular glasses,images form on cylindrical lens elements or a two-dimensional array oflens elements. The stereoscopic image may be provided via opticalmethods, where left and right eye images are provided only to thecorresponding eyes using optical means such as prisms, mirror(s),lens(es), and the like. Large convex or concave lenses can also be usedto receive two separately projected images to the user.

In one embodiment, eyewear 140 may be used as a position input device totrack the user view (e.g., eyepoint or point of view (POV)) of a userviewing a 3D scene presented by the system 100A. For example, eyewear140 may provide information (e.g., position information, which includesorientation information, etc.) that is usable to determine the positionof the point of view of the user, e.g., via triangulation. In someembodiments, the position input device may use a light sensitivedetection system, e.g., may include an infrared detection system, todetect the position of the viewer's head to allow the viewer freedom ofhead movement. Other embodiments of the input device(s) may use thetriangulation method of detecting the viewer point of view location,such as one or more sensors (e.g., two cameras, such as chargecoupled-device (CCD) or complementary metal oxide semiconductor (CMOS)cameras) providing position data suitable for the head tracking. Theinput device(s), such as a stylus, keyboard, mouse, trackball, joystick,or the like, or combinations thereof, may be manually operated by theviewer to specify or indicate the correct display of the horizontalperspective display images. However, any method for tracking theposition of the user's head or point of view may be used as desired.Accordingly, the 3D scene may be rendered from the perspective (or pointof view) of the user such that the user may view the 3D scene withminimal distortions (e.g., since it is based on the point of view of theuser). Thus, the 3D scene may be particularly rendered for the point ofview of the user, using the position input device.

The relationships among the position of the display(s) 150 and the pointof view of the user may be used to map a portion of the virtual space tothe physical space of the system 100A. In essence, the physical spaceand components used may be mapped to the virtual model in order toaccurately render a 3D scene of the virtual space.

One or more of the user input devices (e.g., the keyboard 120, the mouse125, the user input device 130, pointing device, user control device,user hand/fingers, etc.) may be used to interact with the presented 3Dscene. For example, the user input device 130 (shown as a stylus) orsimply the user's hands may be used to directly interact with virtualobjects of the 3D scene (via the viewed projected objects). Such directinteraction may be possible with negative space portions of the 3Dscene. In some embodiments, at least a portion of the 3D scene may bepresented in this negative space, which is in front of or otherwiseoutside of the at least one display, via stereoscopic rendering (of the3D scene). In some embodiments, at least a portion of the 3D scene mayappear as a hologram-like image above the surface of the display 150.For example, when the horizontal display 150B is used, the 3D scene maybe seen as hovering above the horizontal display. It should be noted,however, that a portion of the 3D scene may also be presented asappearing behind the display surface, which is in positive space Thus,negative space refers to a space which the user is able to freely movein and interact with (e.g., where the user is able to place his hands(or more generally, user input device 130) in the space), as opposed toa space the user cannot freely move in and interact with (e.g., wherethe user is not able to place his hands (or a user input device 130) inthe space, such as below the display surface). Thus, negative space maybe considered to be a “hands-on volume” as opposed to an “inner-volume”(i.e., positive space), which may be under the surface of thedisplay(s), and thus not accessible. Thus, the user may interact withvirtual objects in the negative space because they are proximate to theuser's own physical space. Said another way, the positive space islocated behind (or under) the viewing surface, and so presented objectsappear to be located inside (or on the back side of) the physicalviewing device. Thus, objects of the 3D scene presented within thepositive space do not share the same physical space with the user andthe objects therefore cannot be directly and physically manipulated byhands or physically intersected by hand-held tools such as user inputdevice 130. Rather, they may be manipulated indirectly, e.g., via acomputer mouse, a joystick, virtual representations of hands, handheldtools, or a stylus, or by projections from the stylus (e.g., a virtuallaser or a virtual plane).

In some embodiments, system 100A may include one or more sensors 160.The one or more sensors 160 may be included in a tracking system. FIG. 3illustrates an embodiment using four cameras 160. For instance, two ofthe four cameras 160 may be used to sense a user view (e.g., point ofview) and the other two cameras 160 may be used to sense a user inputdevice (e.g., pointing device, stylus, hand, glove, etc.).Alternatively, fewer than four sensors may be used (e.g., two sensors),wherein each sensor may track both the user (e.g., the user's headand/or the user's point of view) and the user input device. Sensors 160may be used to image a user of system 100A, track a user's movement, ortrack a user's head or eyes, among other contemplated functions. In oneembodiment, cameras 160 may track a position and/or an orientation ofuser input device 130. The information regarding the position (includingthe orientation) of the user input device 130 provided by the one ormore sensors 160 may be used in conjunction with other positionalinformation of the system (e.g., an accelerometer and/or gyroscopewithin the stylus itself) to perform more precise 3D tracking of theuser input device 130. The one or more sensors 160 may be spatiallyseparated from one another and placed in a position to view a volumethat encompasses where a user will view stereo imagery. Sensors 160 mayalso be far enough apart from each other to provide for a separation ofview for a true three-axis triangulation determination. System 100A mayalso include a caddy 170 to store user input device 130. Caddy 170 mayalso be used to calibrate the orientation of the stylus to a known roll,pitch, and yaw, and so may be in a fixed position relative to cameras160.

In one embodiment, the system 100A may be configured to couple to anetwork, such as a wide area network, via an input. The input may beconfigured to receive data (e.g., image data, video data, audio data,etc.) over the network from a system similar to system 100A. In otherembodiments, a tracking system may include cameras 160. Cameras 160 maybe configured to provide visual information regarding a user (e.g., suchthat a POV, e.g., the position (including the orientation), of the usermay be determined or such that a position of the user's hand may bedetermined). However, it should be noted that any type of varioustracking techniques or devices may be used as desired. Note that as usedherein, POV of a user refers to the perspective or POV from which a useroptically views an object or image, i.e., a user's visual POV, and thusis defined with respect to the display device of the system. In someembodiments, the POV may be a 6 degree of freedom (6DOF) POV, e.g.,three location coordinates and three orientation coordinates, althoughany POV may be used as desired, e.g., three location coordinates and twoor three orientation coordinates, and so forth. As noted above, positioncoordinates may include both location and orientation coordinates.

Note that in some embodiments, the tracking system may rely at least inpart on the components of chassis 110A to determine a position or a POV,e.g., via execution of one more programs by or on a processor orfunctional unit of chassis 110A, although in other embodiments thetracking system may operate independently, e.g., may have its ownprocessor or functional unit.

In certain embodiments, the system may include components implementing aperspective based image capture system, for capturing images of a targetobject at a location remote from the system. For example, theperspective based image capture system may include an input configuredto couple to a network for receiving information regarding a point ofview (POV) from a tracking system at a remote location. The informationregarding the POV may indicate a position of a remote user. Theperspective based image capture system may further include another imagecapture system for capturing images of a target object. Morespecifically, the image capture system may be configured to capture oneor more images from a first perspective based on the informationregarding the POV received by the input.

The user may be able to specify or otherwise manipulate a virtualviewpoint within the 3D scene presented by the display(s) 150. A view ofthe 3D scene may be presented based on the virtual viewpoint, either byone or more of the display(s) 150 or another display, as desired. Thisview of the 3D scene may be stereoscopic or monoscopic, as desired.

A 3D scene generator (e.g., content processing system) stored andexecuted in the chassis 110A may be configured to dynamically change thedisplayed images provided by the display(s) 150. More particularly, the3D scene generator may update the displayed 3D scene based on changes inthe user view, user control (e.g., manipulations via the user inputdevices), etc. Such changes may be performed dynamically at run-time,and may be performed in real time. The 3D scene generator may also keeptrack of peripheral devices (e.g., user input device 130 or eyewear 140)to ensure synchronization between the peripheral device and thedisplayed image. The system may further include a calibration unit,procedure, and/or fiducial markers to ensure proper mapping of theperipheral device to the display images and proper mapping between theprojected images and the virtual images stored in the memory of thechassis 110A.

Thus, the system 100A may present a 3D scene with which the user mayinteract in real time. The system may include real-time electronicdisplay(s) 150 that may present or convey perspective images in the openspace, and user input device 130 that may allow the user to interactwith the 3D scene with hand controlled or hand-held tools. The system100A may also include means to manipulate the displayed image in variousways, such as magnification, zoom, rotation, or movement, or even todisplay a new image. However, as noted above, in some embodiments, thesystem may facilitate such manipulations via the user's hands, e.g.,without hand-held tools.

Further, while the system 100A is shown as including horizontal display150B because it simulates the user's visual experience with thehorizontal ground, other viewing surfaces may offer similar 3D illusionexperiences. For example, the 3D scene may appear to be hanging from aceiling by projecting the horizontal perspective images onto a ceilingsurface, or may appear to be floating from a wall by projectinghorizontal perspective images onto a vertical wall surface. Moregenerally, any other variations in display orientation and perspective(or any other configuration of the system 100A) may be used as desired.

According to various embodiments of the present disclosure, the display150 may display various types of information (for example, multimediadata or text data) to be provided to the user. The display 150 may beconfigured to include a liquid crystal display (LCD), a light emittingdiode (LED) display, an organic LED (OLED) display, a plasma celldisplay, an electronic ink array display, an electronic paper display, aflexible LCD, a flexible electrochromic display, or a flexible electrowetting display. The display 150 may be connected functionally to anelement(s) of the electronic device. Also, the display 150 may beconnected functionally to an electronic device(s) other than theelectronic device.

In the exemplary embodiment of FIG. 3B, computer system 100B may includechassis 110B which may include display 150, keyboard 120, trackpad ortouchpad 135, and at least two cameras 160. The computer system 100B mayalso include user input device 130 and eyewear 140. Note that in someembodiments, computer system 100B may be wireless or mobile station,e.g., such as a wireless station 106 further described below. Forexample, computer system 100B may be or included on mobile telephones orsmart phones (e.g., iPhone™, Android™-based phones), tablet computers(e.g., iPad™, Samsung Galaxy™, etc.), laptop computers (e.g., MacBook™),portable gaming devices (e.g., Nintendo DS™, PlayStation Portable™,Gameboy Advance™, iPhone™), portable Internet devices, and/or otherhandheld devices. In various embodiments, at least one of the display150 may be a stereoscopic display. It is noted that a stereoscopicdisplay may also be configured to display two-dimensional (2D) objectsand may be configured to operate in a 2D mode.

The chassis 110B may include various computer components such asprocessors, at least one memory medium (e.g., RAM, ROM, hard drives,etc.), graphics circuitry, audio circuitry, and other circuitry forperforming computer tasks, such as those described herein. The at leastone memory medium may store one or more computer programs or softwarecomponents according to various embodiments of the present invention.For example, the memory medium may store one or more graphics engineswhich are executable to perform some of the techniques described herein.In certain embodiments, the graphics engine may be implemented on or bya functional unit or processing element. As used herein, and as noted inthe Terms section above, the term functional unit or processing elementrefers to any of various elements or combinations of elements configuredto process instructions and/or data. Processing elements include, forexample, circuits such as an ASIC (Application Specific IntegratedCircuit), portions or circuits of individual processor cores, entireprocessor cores, individual processors, programmable hardware devicessuch as a field programmable gate array (FPGA), and/or larger portionsof systems that include multiple processors, as well as any combinationsthereof.

The memory medium (which may include two or more memory mediums) mayalso store data (and/or program instructions) (e.g., implementing orspecifying a computer model) representing a virtual space, which may beused for projecting a 3D scene, such as scene 180, of the virtual spacevia the display(s) 150. Further, the memory medium may store softwarewhich is executable to perform three-dimensional spatial tracking (e.g.,user view tracking, user control tracking, etc.), content processing, orother features, as described herein. For example, the computer systemmay include a tracking system that may track one or more of a user'shead, a user's hand, or the stylus. Additionally, the memory medium maystore operating system software, as well as other software for operationof the computer system. Various embodiments further include receiving orstoring instructions and/or data implemented in accordance with theforegoing description upon a carrier medium.

As indicated above, the computer system 100B (or more specifically,chassis 110B) may be configured to display a three-dimensional (3D)scene (e.g., via stereoscopic images), or 3D content, such as scene 180,using the display 150. The computer system 100B may also be configuredto display a “view” of the 3D scene using the display 150. The “view” ofthe 3D scene, or content, may refer to a displayed portion of the 3Dscene from a viewpoint within the 3D scene. A viewpoint within the 3Dscene may be referred to as a “virtual viewpoint.” The view may bestereoscopic, e.g., may be displayed on a stereoscopic display.Alternatively, the view may be monoscopic (not stereoscopic), and may bedisplayed on either a monoscopic display or a stereoscopic display. Notethat a monoscopic image or scene displayed on a stereoscopic display mayappear the same as on a monoscopic display system.

In some embodiments, the display 150 may present a 3D scene for theuser. This 3D scene may be considered or referred to as an illusion orsimulated 3D because the actual provided images are 2D, but the scene isconveyed in 3D via the user's interpretation of the provided images viastereoscopic effects. In order to properly view the stereoscopic images(one for each eye for each image frame), the user may wear eyewear 140.Eyewear 140 may be any of anaglyph glasses, polarized glasses, shutterglasses, lenticular glasses, etc., among others.

In some embodiments, eyewear 140 may be used as a position input deviceto track the user view (e.g., eyepoint or point of view (POV)) of a userviewing a 3D scene presented by the system 100B. For example, eyewear140 may provide information (e.g., position information, which includesorientation information, etc.) that is usable to determine the positionof the point of view of the user, e.g., via triangulation. In someembodiments, the position input device may use a light sensitivedetection system, e.g., may include an infrared detection system, todetect the position of the viewer's head to allow the viewer freedom ofhead movement. Other embodiments of the input device(s) may use thetriangulation method of detecting the viewer point of view location,such as one or more sensors (e.g., two cameras, such as chargecoupled-device (CCD) or complementary metal oxide semiconductor (CMOS)cameras) providing position data suitable for the head tracking. Theinput device(s), such as a stylus, keyboard, mouse, trackball, joystick,or the like, or combinations thereof, may be manually operated by theviewer to specify or indicate the correct display of the horizontalperspective display images. However, any method for tracking theposition of the user's head or point of view may be used as desired.Accordingly, the 3D scene may be rendered from the perspective (or pointof view) of the user such that the user may view the 3D scene withminimal distortions (e.g., since it is based on the point of view of theuser). Thus, the 3D scene may be particularly rendered for the point ofview of the user, using the position input device.

The relationships among the position of the display 150 and the point ofview of the user may be used to map a portion of the virtual space tothe physical space of the system 100B. In essence, the physical spaceand components used may be mapped to the virtual model in order toaccurately render a 3D scene of the virtual space.

One or more of the user input devices (e.g., the keyboard 120, thetrackpad 135, the user input device 130, pointing device, user controldevice, user hand/fingers, etc.) may be used to interact with thepresented 3D scene. For example, the user input device 130 (shown as astylus) or simply the user's hands may be used to directly interact withvirtual objects of the 3D scene (via the viewed projected objects). Suchdirect interaction may be possible with negative space portions of the3D scene. In some embodiments, at least a portion of the 3D scene may bepresented in this negative space, which is in front of or otherwiseoutside of the at least one display, via stereoscopic rendering (of the3D scene). In some embodiments, at least a portion of the 3D scene mayappear as a hologram-like image above the surface of the display 150. Itshould be noted, however, that a portion of the 3D scene may also bepresented as appearing behind the display surface, which is in positivespace Thus, negative space refers to a space which the user is able tofreely move in and interact with (e.g., where the user is able to placehis hands (or more generally, user input device 130) in the space), asopposed to a space the user cannot freely move in and interact with(e.g., where the user is not able to place his hands (or a user inputdevice 130) in the space, such as below the display surface). Thus,negative space may be considered to be a “hands-on volume” as opposed toan “inner-volume” (i.e., positive space), which may be under the surfaceof the display(s), and thus not accessible. Thus, the user may interactwith virtual objects in the negative space because they are proximate tothe user's own physical space. Said another way, the positive space islocated behind (or under) the viewing surface, and so presented objectsappear to be located inside (or on the back side of) the physicalviewing device. Thus, objects of the 3D scene presented within thepositive space do not share the same physical space with the user andthe objects therefore cannot be directly and physically manipulated byhands or physically intersected by hand-held tools such as user inputdevice 130. Rather, they may be manipulated indirectly, e.g., via acomputer mouse, a joystick, virtual representations of hands, handheldtools, or a stylus, or by projections from the stylus (e.g., a virtuallaser or a virtual plane).

In some embodiments, system 100 may include one or more sensors 160. Theone or more sensors 160 may be included in a tracking system. FIG. 3Billustrates an embodiment using four cameras 160. For instance, two ofthe four cameras 160 may be used to sense a user view (e.g., point ofview) and the other two cameras 160 may be used to sense a user inputdevice (e.g., pointing device, stylus, hand, glove, etc.).Alternatively, fewer than four sensors may be used (e.g., two sensors),wherein each sensor may track both the user (e.g., the user's headand/or the user's point of view) and the user input device. Sensors 160may be used to image a user of system 100B, track a user's movement, ortrack a user's head or eyes, among other contemplated functions. In oneembodiment, cameras 160 may track a position and/or an orientation ofuser input device 130. The information regarding the position (includingthe orientation) of the user input device 130 provided by the one ormore sensors 160 may be used in conjunction with other positionalinformation of the system (e.g., an accelerometer and/or gyroscopewithin the stylus itself) to perform more precise 3D tracking of theuser input device 130. The one or more sensors 160 may be spatiallyseparated from one another and placed in a position to view a volumethat encompasses where a user will view stereo imagery. Sensors 160 mayalso be far enough apart from each other to provide for a separation ofview for a true three-axis triangulation determination.

In some embodiments, the system 100B may be configured to couple to anetwork, such as a wide area network, via an input or interface (wiredor wireless). The input may be configured to receive data (e.g., imagedata, video data, audio data, etc.) over the network from a systemsimilar to systems 100A or 100B. In other embodiments, a tracking systemmay include cameras 160. Cameras 160 may be configured to provide visualinformation regarding a user (e.g., such that a POV, e.g., the position(including the orientation), of the user may be determined or such thata position of the user's hand may be determined). However, it should benoted that any type of various tracking techniques or devices may beused as desired. Note that as used herein, POV of a user refers to theperspective or POV from which a user optically views an object or image,i.e., a user's visual POV, and thus is defined with respect to thedisplay device of the system. In some embodiments, the POV may be a 6degree of freedom (6DOF) POV, e.g., three location coordinates and threeorientation coordinates, although any POV may be used as desired, e.g.,three location coordinates and two or three orientation coordinates, andso forth. As noted above, position coordinates may include both locationand orientation coordinates.

Note that in some embodiments, the tracking system may rely at least inpart on the components of chassis 110B to determine a position or a POV,e.g., via execution of one more programs by or on a processor orfunctional unit of chassis 110B, although in other embodiments thetracking system may operate independently, e.g., may have its ownprocessor or functional unit.

In certain embodiments, the system may include components implementing aperspective based image capture system, for capturing images of a targetobject at a location remote from the system. For example, theperspective based image capture system may include an input configuredto couple to a network for receiving information regarding a point ofview (POV) from a tracking system at a remote location. The informationregarding the POV may indicate a position of a remote user. Theperspective based image capture system may further include another imagecapture system for capturing images of a target object. Morespecifically, the image capture system may be configured to capture oneor more images from a first perspective based on the informationregarding the POV received by the input.

The user may be able to specify or otherwise manipulate a virtualviewpoint within the 3D scene presented by the display 150. A view ofthe 3D scene may be presented based on the virtual viewpoint, either byone or more of the display 150 or another display, as desired. This viewof the 3D scene may be stereoscopic or monoscopic, as desired.

A 3D scene generator (e.g., content processing system) stored andexecuted in the chassis 110B may be configured to dynamically change thedisplayed images provided by the display 150. More particularly, the 3Dscene generator may update the displayed 3D scene based on changes inthe user view, user control (e.g., manipulations via the user inputdevices), etc. Such changes may be performed dynamically at run-time,and may be performed in real time. The 3D scene generator may also keeptrack of peripheral devices (e.g., user input device 130 or eyewear 140)to ensure synchronization between the peripheral device and thedisplayed image. The system may further include a calibration unit,procedure, and/or fiducial markers to ensure proper mapping of theperipheral device to the display images and proper mapping between theprojected images and the virtual images stored in the memory of thechassis 110B.

Thus, the system 100B may present a 3D scene with which the user mayinteract in real time. The system may include real-time electronicdisplay 150 that may present or convey perspective images in the openspace, and user input device 130 that may allow the user to interactwith the 3D scene with hand controlled or hand-held tools. The system100B may also include means to manipulate the displayed image in variousways, such as magnification, zoom, rotation, or movement, or even todisplay a new image. However, as noted above, in some embodiments, thesystem may facilitate such manipulations via the user's hands, e.g.,without hand-held tools.

According to various embodiments of the present disclosure, the display150 may display various types of information (for example, multimediadata or text data) to be provided to the user. The display 150 may beconfigured to include a liquid crystal display (LCD), a light emittingdiode (LED) display, an organic LED (OLED) display, a plasma celldisplay, an electronic ink array display, an electronic paper display, aflexible LCD, a flexible electrochromic display, or a flexible electrowetting display. The display 150 may be connected functionally to anelement(s) of the electronic device. Also, the display 150 may beconnected functionally to an electronic device(s) other than theelectronic device. According to various embodiments of the presentdisclosure, the input module 240 may receive an input for controlling anattribute of, for example, a history screen. The input module 240 mayreceive, for example, an input of ‘reference screen setting’. ‘Referencescreen setting’ may involve an operation for storing information relatedto the screen in the storage module 210 in order to display thereference screen. The input module 240 may receive, for example, aninput for displaying the reference screen. Attributes of the screen mayinclude, for example, at least one of the position of the referencescreen, a sound volume for the reference screen, brightness of thescreen, and the size of the screen. If the input module 240 is includedin a second electronic device, the input module 240 may not be providedin the electronic device according to various embodiments of the presentdisclosure.

FIG. 4 illustrates an example simplified block diagram of a wirelessstation 106. According to embodiments, wireless station 106 may be auser equipment (UE) device, a mobile device and/or mobile station.Wireless station 106 may be used in conjunction with the systemdescribed above in reference to FIGS. 3A and 3B and the systemsdescribed below in reference to FIGS. 5B and 5C. For example, wirelessstation 106 may be configured as an input device to any of the describedsystems (e.g., wireless station 106 may be configured as a user inputdevice). As another example, according to some embodiments, wirelessstation 106 may be configured as a display of any of the describedsystems. Thus, wireless station 106 may be configured to display astereoscopic image. In some embodiments, wireless station 106 may beconfigured to communicate with a 3D system either wirelessly (e.g., viaa local area network such as a Wi-Fi, Bluetooth, or Bluetooth low energyconnection) or via a wired interface such as a universal serial businterface, among other wired interfaces. In some embodiments, wirelessstation 106 may be included in a computer system, such as computersystem 100B described above.

As shown, the wireless station 106 may include a system on chip (SOC)300, which may include portions for various purposes. The SOC 300 may becoupled to various other circuits of the wireless station 106. Forexample, the wireless station 106 may include various types of memory(e.g., including NAND flash 310), a connector interface (I/F) (or dock)320 (e.g., for coupling to a computer system, dock, charging station,etc.), the display 360, cellular communication circuitry 330 such as forLTE, GSM, etc., and short to medium range wireless communicationcircuitry 329 (e.g., Bluetooth™ and WLAN circuitry). The wirelessstation 106 may further include one or more smart cards 310 thatincorporate SIM (Subscriber Identity Module) functionality, such as oneor more UICC(s) (Universal Integrated Circuit Card(s)) cards 345. Thecellular communication circuitry 330 may couple to one or more antennas,such as antennas 335 and 336 as shown. The short to medium rangewireless communication circuitry 329 may also couple to one or moreantennas, such as antennas 337 and 338 as shown. Alternatively, theshort to medium range wireless communication circuitry 329 may couple tothe antennas 335 and 336 in addition to, or instead of, coupling to theantennas 337 and 338. The short to medium range wireless communicationcircuitry 329 may include multiple receive chains and/or multipletransmit chains for receiving and/or transmitting multiple spatialstreams, such as in a multiple-input multiple output (MIMO)configuration.

As shown, the SOC 300 may include processor(s) 302, which may executeprogram instructions for the wireless station 106 and display circuitry304, which may perform graphics processing and provide display signalsto the display 360. The processor(s) 302 may also be coupled to memorymanagement unit (MMU) 340, which may be configured to receive addressesfrom the processor(s) 302 and translate those addresses to locations inmemory (e.g., memory 306, read only memory (ROM) 350, NAND flash memory310) and/or to other circuits or devices, such as the display circuitry304, cellular communication circuitry 330, short range wirelesscommunication circuitry 329, connector interface (I/F) 320, and/ordisplay 360. The MMU 340 may be configured to perform memory protectionand page table translation or set up. In some embodiments, the MMU 340may be included as a portion of the processor(s) 302.

As described herein, the wireless station 106 may include hardware andsoftware components for implementing the features described herein,e.g., the wireless station 106 may form at least part of a 3D displaysystem such as system 100 described above and/or systems 500A and 5Bdescribed below. For example, the processor 302 of the wireless station106 may be configured to implement part or all of the features describedherein, e.g., by executing program instructions stored on a memorymedium (e.g., a non-transitory computer-readable memory medium).Alternatively (or in addition), processor 302 may be configured as aprogrammable hardware element, such as an FPGA (Field Programmable GateArray), or as an ASIC (Application Specific Integrated Circuit).Alternatively (or in addition) the processor 302 of the UE 106, inconjunction with one or more of the other components 300, 304, 306, 310,320, 330, 335, 340, 345, 350, 360 may be configured to implement part orall of the features described herein.

In addition, as described herein, processor 302 may include one or moreprocessing elements. Thus, processor 302 may include one or moreintegrated circuits (ICs) that are configured to perform the functionsof processor 302. In addition, each integrated circuit may includecircuitry (e.g., first circuitry, second circuitry, etc.) configured toperform the functions of processor(s) 302.

Referring to FIG. 5A, a head-mounted electronic device 500A may includea body 502A and a cover 504. The body 502 may include lenses 508 and510, and a control device 514. In addition, electronic device 500A mayinclude a support 506A which may be configured to support electronicdevice 500A on a user's head. Lenses 508 and 510 may be positioned tocorrespond to eyes of a user. The user may view a screen on a displaythrough lenses 508 and 510. The display may be coupled or connected toelectronic device 500. In some embodiments, the display may be includedon (or in) cover 504 and cover 504 may be configured to couple to body502A. In some embodiments, electronic device 500B may include a display,such as display 150A or 150B described above in reference to FIG. 4.Thus, cover 504 may be communicatively coupled to body 502A (e.g., tocouple a display of cover 504 to a processor of electronic device 500)and mechanically coupled (e.g., attached to) body 502. In someembodiments, the communicative coupling between body 502A and cover 504may be wired and/or wireless.

In some embodiments, control device 514 may be located on a side surfaceof body 502A. Control device 514 may be used for the user to enter aninput for controlling the head-mounted electronic device 500A. Forexample, control device 514 may include a touch panel, a button, a wheelkey, and/or a touch pad. The touch panel may receive the user's touchinput. The touch input may be a direct touch input to the touch panel ora hovering input in the vicinity of the touch panel.

Turning to FIG. 5B, a head-mounted electronic device 500B may include abody 502B and a support 506B. Body 502B may be configured to couple to awireless station and a display of electronic device 500B may be adisplay of a wireless station, such as wireless station 106, and thewireless station may be coupled or connected to (e.g., may be detachablymounted to) electronic device 500B. In other words, electronic device500B may be configured such that a wireless station may benon-permanently coupled to, and removable without destructive measures,to electronic device 500B. Thus, electronic device 500B may be coupledto and decoupled from (e.g., non-destructively decoupled from) awireless station without a change in functionality of the wirelessstation or electronic device 500B.

Turning to FIG. 5C, FIG. 5C illustrates an example simplified blockdiagram of a head-mounted electronic device 500C. According toembodiments, electronic device 500C may be include a display (e.g., suchas electronic device 500A) or may be configured to couple to wirelessstation (e.g., such as electronic device 500B). Note that electronicdevices 500A and 500B described above may include at least portions ofthe features described in reference to electronic device 500C.

As shown, the electronic device 500C may include a system on chip (SOC)506, which may include portions for various purposes. The SOC 506 may becoupled to various other circuits of the electronic device 500C. Forexample, the electronic device 500C may include various types of memory(e.g., including NAND flash 510), a connector interface (I/F) (or dock)520 (e.g., for coupling to a computer system, dock, charging station,external display, etc.), the display 560 (note that is some embodiments,electronic device 500C may not include display 560), and short to mediumrange wireless communication circuitry 529 (e.g., Bluetooth™ and WLANcircuitry). The short to medium range wireless communication circuitry529 may also couple to one or more antennas, such as antennas 537 and538 as shown. The short to medium range wireless communication circuitry529 may include multiple receive chains and/or multiple transmit chainsfor receiving and/or transmitting multiple spatial streams, such as in amultiple-input multiple output (MIMO) configuration.

As shown, the SOC 506 may include processor(s) 502, which may executeprogram instructions for the electronic device 500C and displaycircuitry 504, which may perform graphics processing and provide displaysignals to the display 560 (and/or to dock 520). The processor(s) 502may also be coupled to memory management unit (MMU) 540, which may beconfigured to receive addresses from the processor(s) 502 and translatethose addresses to locations in memory (e.g., memory 506, read onlymemory (ROM) 550, NAND flash memory 510) and/or to other circuits ordevices, such as the display circuitry 504, short range wirelesscommunication circuitry 529, connector interface (I/F) 520, and/ordisplay 560. The MMU 540 may be configured to perform memory protectionand page table translation or set up. In some embodiments, the MMU 540may be included as a portion of the processor(s) 502.

In some embodiments, electronic device 500C (and/or an electronic devicesuch as electronic device 500A or 500B) may be in communication with auser input device, such as user input device 130 described above. Insome embodiments, the electronic device may receive user input via userinput device 130 as described above.

In addition, in some embodiments, electronic device 500C may include oneor more positional sensors such as accelerometers, gyroscopic sensors,geomagnetic sensors, magnetic sensors, proximity sensors, gesturesensors, grip sensors, and/or biometric sensors. In some embodiments,the electronic device may acquire information for determining a motionof a user wearing the electronic device and/or whether a user wears orremoves electronic device 500C, using the one or more positionalsensors. The at least one processor may control execution of afunction(s) or an operation(s) corresponding to an input receivedthrough a control device (for example, control device 514 and/or userinput device 130) in response to a received input.

As described herein, the electronic device 500C may include hardware andsoftware components for implementing the features described herein,e.g., the electronic device 500C may form at least part of a 3D displaysystem such as system 100 described above and/or systems 500A and 5Bdescribed below. For example, the processor 502 of the electronic device500C may be configured to implement part or all of the featuresdescribed herein, e.g., by executing program instructions stored on amemory medium (e.g., a non-transitory computer-readable memory medium).Alternatively (or in addition), processor 502 may be configured as aprogrammable hardware element, such as an FPGA (Field Programmable GateArray), or as an ASIC (Application Specific Integrated Circuit).Alternatively (or in addition) the processor 502 of the UE 106, inconjunction with one or more of the other components 500, 504, 506, 510,520, 535, 550, 560 may be configured to implement part or all of thefeatures described herein.

In some embodiments, electronic device 500C may include or be incommunication with one or more external cameras. For example, electronicdevice 500C may include (or be in communication with) one or morecameras (or an array of cameras) that may be configured to captureimages of a physical location of a user.

In addition, as described herein, processor 502 may include one or moreprocessing elements. Thus, processor 502 may include one or moreintegrated circuits (ICs) that are configured to perform the functionsof processor 502. In addition, each integrated circuit may includecircuitry (e.g., first circuitry, second circuitry, etc.) configured toperform the functions of processor(s) 502.

FIG. 6 illustrates an example of a user input device, according to someembodiments. As shown, a user input device 600 may be configured toperform various embodiments as described herein. User input device 600may be similar to or the same as user input device 130 as describedabove in reference to FIGS. 4 and 5B-5C. Thus, user input device 600 maybe used in conjunction with, or be included in, system 100 or systems500 and 550. As described above, systems 100, 500, and 550 may have thecapability to determine the six-axis position and orientation of userinput device 600. Note that this includes the X, Y, Z location of tip610 of user input device 600 and the a, (3, y angular orientation ofbody 602 of user input device 600. However, it should be further notedthat user input device 600 is exemplary, and that other user inputdevices, suitably configured, may be used as desired.

As shown, user input device 600 may include buttons 604, 606, and 612.One of the buttons, such as button 606, may be depressed and held downto trigger the selection of an object within a 3D scene presented by anyof systems 100, 500, and 550. Additionally, system 100 may be configuredto display a virtual “laser like” projection from tip 610 to theselected object. With the object selected, adjustment of the positionand/or orientation of user input device 600 may change the positionand/or orientation of the object. Thus, movements of the user inputdevice 600 may result in corresponding translations and/or rotations ofthe object.

FIGS. 7A-B and 8—Exemplary LCD Systems

FIG. 7A illustrate example liquid crystal display (LCD) systems that mayincorporate a variable drive voltage, and which may be configured withvarious embodiments described below. As examples of LCD systems, FIG. 7Aillustrates an LCD monitor 700 a (e.g., an LCD computer monitor and/oran LCD television) which may be included in a computer system such ascomputer system 100A described above, shutter glasses 700 b, as well asuser equipment devices (UEs) 700 c-e (e.g., portable computer 700 c,mobile phone 700 d, and tablet 700 e) which may be included in computersystem such as computer system 100B described above, and head mounteddisplay 700 f. Other systems that drive twisted-nematic junctions mayalso incorporate a variable drive voltage, such as an organic lightemitting diode (OLED) system that includes a polarization switch. Insome embodiments, LCD systems 700 a-f may include light source 702,control circuitry 704, LCD panel 706, and a liquid crystal device, suchas polarization switch 708 as further described below in reference toFIG. 7B.

FIG. 7B illustrates an example of a schematic diagram of an LCD system,such as system 700, according to some embodiments. Note that LCD system700 may be included in any of the systems described above. In someembodiments, light source 702 may be coupled to (or in communicationwith) control electronics (circuitry) 704, LCD panel 706, andpolarization switch 708. Light source 702 may receive power and/orcontrol indications from control circuitry 704. In turn, light source702 may provide light to LCD panel 706 and polarization switch 708.Light source 702 may be referred to as a backlight. In some embodiments,light source 702 may include a plurality of light emitting diodes (LEDs)that may provide pulses of light to various components of LCD system700. The backlight may, in various embodiments, be segmented (e.g., asfurther described below). In some embodiments, the backlight may besegmented into a plurality of independently addressable rows (e.g., 4,5, 8, 10, 16, and so forth). For example, light source 702 may besegmented into sections that may extend (at least partially) acrosshorizontal bands of the display. The LEDs of light source 702 may pulseat different times, which may be optimized for timing one segment'spulse separate from other segments. Further, a segmented light source702 may include segmented light guides that may help minimize row-to-rowcrosstalk. Light source 702 may be positioned in LCD system 700 behindLCD panel and polarization switch from the perspective of the front ofLCD system 700 (e.g., where a user/viewer would be located). In someembodiments, the LEDs may be edge LEDs that provide illumination fromboth sides of LCD system 700. Light source 702 may redirect theillumination from the edge LEDs so that the illumination may beperpendicular to LCD panel 706 and polarization switch 708. LCD system700 may additionally include an enclosure that may include heatsinks forthe LEDs. In that manner, heat produced by the LEDs may be dissipatedand alleviate the effects on other LCD system 700 components, such aspolarization switch 708. As described herein, light source 702 may beshifted, or extended, in conjunction with the variable drive voltage,according to some embodiments. In an embodiment in which the system isshutter glasses, the shutter glasses may not require any backlightpulsing. As such, an accompanying LCD as part of such a system mayinclude a backlight capable of being pulsed, or in some embodiments, itmay include a light source that is incapable of being pulsed (e.g., acold cathode fluorescent light (CCFL)).

In some embodiments, LCD system 700 may include control circuitry 704.Control circuitry 704 may receive a voltage from a voltage source (notshown). Control circuitry 704 may, in turn, provide one or more voltagesand/or other indications to light source 702, LCD panel 706, and/orpolarization switch 708. As an example, control circuitry 704 mayprovide a voltage and a backlight enable indication to light source 702,which, in turn, may cause light source 702 to provide a light pulse toLCD panel 706 and polarization switch 708. In some embodiments, controlcircuitry 704 may independently address different segments of lightsource 702, LCD panel 706, and polarization switch 708. For example,control circuitry 704 may provide a voltage and a backlight enableindication to a backlight driver board (not shown) of light source 702.Light source 702 may then provide appropriate pulsed voltages to eachindependently addressable segment of light source 702. In someembodiments, control circuitry 704 may provide a pulsed voltage directlyto each segment of LEDs, without necessarily providing the voltage to abacklight driver board. The addressed light source 702 segment may thenprovide one or more light pulses to LCD panel 706, and polarizationswitch 708. Control circuitry 704 may include circuitry to implement oneor more variable drive voltages to polarization switch 708, according tosome embodiments.

LCD panel 706 may include a plurality of pixels that may collectivelyproduce images. The plurality of pixels of the LC panel may be addressedwith data that conveys the image to be displayed. In some embodiments,LCD panel 706 may be updated from one frame to the next in a progressivescan manner, and hence updating may not occur all at once. In suchembodiments, the pixels of LCD panel 706 may be updated, for example,sequentially by row from top to bottom. As an example, LCD panel 706 mayrefresh at a frequency of 120 Hz (or, in some embodiments 240 or 480Hz). For a 120 Hz system, every 8.3 ms the entire panel's data may beupdated. As another example, for a 240 Hz system, every 4.1 ms theentire panel's data may be updated. Similarly, for a 480 Hz system,every 2.0 ms the entire panel's data may be updated. The transition fromone frame to another may proceed as a progressive scan and the scan maystart at the top row and then proceed through the rest of the rows. Insome embodiments, the time difference from updating the top row toupdating the bottom row may be approximately 5-6 ms. Accordingly, thescan time to write frame data to LCD panel 706 may take a large portionof each frame. As a result, the portion of each frame where the entiredisplay is in the same state may be minimal. The subsequent frames maybe a left eye frame (image) followed by a right eye frame (or viceversa) for a 3D display, or may simply be sequential frames for a 2Ddisplay. In some embodiments, backlight and polarization switchsegmenting may be applied to maintain synchronization with theprogressive scan data write of LCD panel 706. As described herein, anOLED panel may be used in LCD system 700 instead of LCD panel 706 andlight source 702.

LCD system 700 may include a liquid crystal device, such as polarizationswitch 708. Polarization switch 708 may use a twisted-nematic liquidcrystal mode and may include a plurality of distinct individuallyaddressable elements, called segments. Polarization switch 708 mayreceive one or more voltages from control circuitry 704 and may receivea light pulse from light source 702. As was the case with light source702, polarization switch 708 may be segmented into horizontal bands.Polarization switch 708 may be used in LCD system 700 to simultaneouslyprovide a normal black and normal white mode, when used in conjunctionwith the appropriate eyewear, wherein each eye has the appropriate lens.For instance, in the context of an embodiment using the polarizationswitch and corresponding eyewear, where the two lenses of the twoeyepieces of the eyewear are cross polarized, a normal white mode may beprovided in a 3D LCD system 700 for one eye, while concurrently a normalblack mode may be provided for the other eye. Polarization switch 708may control the luminance of LCD system 700. Thus, a normal white modemay allow full luminance in a low voltage state (e.g., 0V) ofpolarization switch 708 while normal black mode may block all luminancefor the corresponding lens of the eyewear. Conversely, a normal whitemode may block all luminance in a driven voltage state (e.g., +/−2.5V,+/−5V, +/−10V, and/or +/−12V), while a normal black mode may allow fullluminance for the corresponding lens of the eyewear. Accordingly, in a3D context, one eye may see an image or frame in a normal white modewhile the other eye sees an image or frame in a normal black mode. Insome embodiments, polarization switch 708 may be a multi-segmentpolarization switch, as described herein.

FIG. 8 is an example of a block diagram of an LCD system, according tosome embodiments. LCD system 800 may be schematically similar to or thesame as LCD system 700 of FIG. 7B and may be configured with variousembodiments described below.

LCD system 800 may include voltage source 802, control circuitry 804,liquid crystal devices, such as a polarization switch 808, shown assegments of a multi-segment polarization switch, LCD panel 810, andlight source 812. Control circuitry 804 may include drive module 806. Insome embodiments, voltage source 802 may be a power supply for LCDsystem 800 or may receive one or more voltages from an external powersupply. Voltage source 802 may output one or more voltages. The one ormore voltages may be provided to control circuitry 804. In someembodiments, voltage source 802 may also provide one or more voltagesdirectly to LCD panel 810, light source 812, a polarization switch 808,or other components (not shown) of LCD system 800. The one or morevoltages may be provided to control circuitry 804, and, in turn, to thepolarization switch 808, may be a drive voltage. The illustratedembodiment shows control circuitry 804 and voltage source 802 asseparate modules, yet, in some embodiments, voltage source 802 may be asubcomponent of control circuitry 804.

In some embodiments, control circuitry 804 may receive the voltage fromvoltage source 802 and provide a drive voltage to the polarizationswitch 808. The drive voltage provided to the polarization switch 808may be provided to a liquid crystal addressable element of thepolarization switch, or other liquid crystal device. In someembodiments, the drive voltage may be +/−5 V. In other embodiments, thedrive voltage may be +/−2.5V, +/−10V, or +/−12V, for example. In someembodiments, the drive voltage may maintain an overall DC bias of 0Vacross the liquid crystal addressable element over time. Controlcircuitry 804 may include drive module 806. Drive module 806 may includea programmable waveform generator. In some embodiments, drive module 806may vary the drive voltage it provides to the one or more polarizationswitches 808 as a function of time. For example, the drive voltage mayinclude a driven function portion and a relaxed function portion. Thedriven function may correspond to the portion of the drive voltage whentransitioning from a low, or relaxed voltage, to a high, or drivenvoltage. Similarly, the relaxed function may correspond to the portionof the drive voltage when transitioning from a driven voltage to arelaxed voltage. In some embodiments, the driven function may be anormal step function while the relaxed function may be one or more of anumber of alternative functions, not equivalent to a step function. Insome embodiments, the relaxed function may be continuous, e.g., in ananalog manner. For instance, the relaxed function may be a decreasingportion of a Gaussian or cosine function. In some embodiments, the drivevoltage function(s) may vary from frame to frame. For instance, liquidcrystal response time may vary as a function of temperature.Accordingly, control circuitry 804 may include a temperature sensor thatmay affect the voltage level and/or shape of the drive voltage waveform.

Further, in various embodiments, the relaxed function may rapidly reducethe drive voltage to an intermediate voltage before slowly reducing thedrive voltage from the intermediate voltage a relaxed voltage (e.g., 0V,corresponding to the relaxed state). For example, if the driven voltagelevel is +/−5V, the relaxed function may rapidly reduce the voltage to+/−0.5V and then slowly reduce the voltage to 0V. Thus, the reductionmay occur at different rates, for example a first and second rate, withthe second rate being lower than the first rate. In such embodiments,control circuitry 804 may drive the polarization switch 808 at fullrate, then transition to a lower intermediate drive voltage inanticipation of the transition to the relaxed state. The intermediatedrive voltage may be close to the threshold of the relaxed state, yetthe one or more polarization switches may maintain optical propertiesconsistent with the driven state. Maintaining the optical propertiesconsistent with the driven state is used herein to mean that the normalblack mode should allow approximately full luminance and the normalwhite mode should block approximately all luminance. The threshold ofthe relaxed state may be approximately 0.2-2V. In some embodiments, therelaxed function may consist of small decremented step functions thatapproximate a continuous waveform.

The drive voltage applied to the polarization switch 808 may present asa variety of different waveforms and timings. For example, the waveformcould be an arbitrary descending waveform, a linear descending ramp, orother waveform. Some factors that may be considered in determining thewaveform and timing may include: contrast level, the presence ofghosting/crosstalk, balance between left and right eye performance, andcolor in bright and dark states. In some embodiments, the drive voltageswing and offset may be varied. Further, in some embodiments, the drivevoltage may be a pulse-width modulated (PWM) waveform, as describedherein.

In some embodiments, different drive voltages may be provided todifferent segments, of a segmented polarization switch 808. Forinstance, as described herein, a polarization switch 808 may besegmented into five different segments. A different phase-shifted drivevoltage, each of which may have a function (e.g., cosine) applied to thehigh-low-voltage transition, may be provided to each of the segments. Asan example, the provided voltage may be independently driven to provideeach segment with an independent and time-shifted voltage from theindependently driven voltages being provided to each other segment. Insuch an embodiment, the timing of the polarization switch transitionsmay be synchronized with the timing of the backlight pulses and the dataof the frames.

In some embodiments, control circuitry 804 may supply one or morevoltages and/or other indications to LCD panel 810 and light source 812,in addition to, the one or more polarization switches 808. The voltagesmay be driven in a different manner than the one or more voltagesprovided to polarization switches 808. As an example, control circuitry804 may provide a voltage, and a power-on indication to LCD panel 810and/or light source 812. Control circuitry 804 may also provide abacklight enable indication to light source 812. Control circuitry 804may, in some embodiments, receive an indication of data writes to LCDpanel 810, from LCD panel 810, or from another source (e.g., an externalsource such as a set-top box, Ethernet, Wi-Fi, DVD player, Blu-Rayplayer, etc.). Control circuitry 804 may include circuitry tosynchronize the drive voltage to the one or more polarization switchesand to left and right frame timing. Control circuitry 804 may furtherinclude circuitry to synchronize backlight enable indications with leftand right frame timing. Accordingly, the variable drive voltage,described herein, may be used in conjunction with a shifted or extendedbacklight, to enhance the benefits of the variable drive voltage. Theextended backlight may be segmented, where each of the subsidiarysegments of the main backlight pulse may be shifted accordingly. In someembodiments, and not shown in FIG. 8, control circuitry 804 may receivevideo, manipulate and process the video, and provide it to the LCD panel810.

In some embodiments, one or more polarization switches 808, or otherliquid crystal device with one or more liquid crystal addressableelements, may receive the drive voltage from control circuitry 804 (anddrive module 806). As described above, the drive voltage may have afunction applied to it before reaching polarization switches 808. Insome embodiments, the one or more polarization switches 808 may receivea drive voltage directly from voltage source 802, which may or may notapply a function to the drive voltage. Polarization switches 808 may bea liquid crystal device, such as twisted-nematic panel, homogeneouscells, chiral-homeotropic liquid crystal cells, optically compensatedbirefringence (OCB) cells, pi-cells, etc. Twisted-nematic panels havecells which may twist up to a full 90 degrees in response to a voltagechange, to allow varying degrees of light to pass through.

In various embodiments, LCD system 800 may include only a singlepolarization switch. The polarization switch 808 may cover the entiredisplay of LCD system 800. Accordingly, the single polarization switch808 may change the polarization state of the light emitted by thedisplay. For a 3D display, this may correspond to two different states:one polarization state that is passed by the right eye polarizer andblocked by the left eye polarizer and another polarization state that ispassed by the left eye polarizer and blocked by the right eye polarizer.The polarization switch 808 may be segmented, for example, intohorizontal sections, similar to the backlight segmenting describedherein. Accordingly, by segmenting the polarization switch intohorizontal sections, the correct polarization state may be achieved forcorresponding data on LCD panel 810 at a given time. As one example, thepolarization switch 808 may be divided into five horizontal sections ofequal size. The various segments of polarization switch 808 may besynchronized or timed according to the progressive-scan-based panelwrite times. In some embodiments, a polarization switch 808 may switchstates when the first row of the segment receives new data (i.e., whenLCD panel 810 begins to write data to that row).

LCD panel 810 may include a plurality of pixels that may collectivelyproduce images. The plurality of pixels may be addressed with data thatmay reflect the image to be display. As discussed herein, LCD panel 810may be updated from one frame to the next in a progressive scan mannerand may not occur all at once. In such an embodiment, the pixels of LCDpanel 810 may be updated, for example, sequentially by row from top tobottom. As an example, LCD panel 810 may refresh at a frequency of 120Hz (or at higher rates such as 240 Hz and/or 480 Hz). For a 120 Hzsystem, every 8.3 ms the entire panel's data may be updated. In someembodiments, the time to update the entire panel, from the top row tothe bottom row, may be approximately 5-6 ms. Accordingly, the scan timeto write frame data to LCD panel 810 may take a significant timepercentage of each frame and the portion of each frame where the entiredisplay is in the same state may likewise be minimal. In someembodiments, backlight and polarization switch segmenting timing and/orsegmenting may be applied to maintain synchronization with theprogressive scan data write of LCD panel 810.

In some embodiments, LCD system 800 may include a light source 812.Light source 812 may provide an instance (e.g., a pulse) of the lightsource to the polarization switch 808. Light source 812 may be abacklight, such as incandescent light bulbs, fluorescent lamps, or oneor more light emitting diodes (LEDs). Light source 812 may include oneor more white backlights or different colored backlights (e.g., RGBLEDs). Light source 812 may be positioned in LCD system 800 behind LCDpanel 810 and polarization switch 808 from the perspective of the frontof LCD system 800 (where the viewer would be). In some embodiments, theLEDs may be edge LEDs that provide illumination from both sides of LCDsystem 800. Light source 812 may include a manner in which to redirectthe illumination from the edge LEDs so that the illumination may beperpendicular to LCD panel 810 and polarization switch 808.

In some embodiments, light source 812 may pulse twice per frame time(i.e., once for a left eye frame and once for a right eye frame), witheach pulse being a pulse of limited duration. For example, starting witha driven state, a first pulse of light source 812 may occur after thedrive voltage reduction from the driven state begins. Specifically, inone example, the first pulse may take place during the voltagetransition from the driven state to the relaxed state. A second pulse oflight source 812 may occur during the relaxed state (i.e., before thedrive voltage transitions back to the driven state). In other words, apulse of the light source, or backlight enable, may be shifted to alater time for the period when the polarization switch drive voltage hasa function applied during the high to low voltage transition. In someembodiments, both pulses of a light source in a frame time may beshifted later in time. When both pulses of a light source are shiftedlater in time, however, the shifted amount may be different for eachpulse. For example, the pulse of light source that may occur during thedriven-to-relaxed state transition may be shifted 2 ms later in timewhile the second pulse of a light source in a frame time may be shifted1 ms later. Therefore, the pulses from light source 812 may not bespaced equally apart from one frame time to the next. In someembodiments, the backlight may be extended in terms of pulse duration.For example, one pulse of light source 812 may begin before the drivevoltage transitions from the driven to the relaxed state but maycomplete after the voltage transition is complete. Thus, elaborating onthe example, if a light pulse is typically 2 ms, then extending thelight pulse may increase its duration to 3 ms. Extending or shifting thebacklight may enable more of the data of LCD panel 810 to be in asteady, same state for a frame and a polarization switch 808 to be in anappropriate state when the backlight is enabled. When used inconjunction with the variable drive voltage, in which optical bounce maybe minimized, shifting the backlight into the minimal optical bounceperiod may produce only a minimal amount of light leakage in the normalwhite state and a minimal drop in luminance for the normal black state.In some embodiments, the time difference between the start of the firstpulse of limited duration and the start of the second pulse of limitedduration in a frame may be less than the time difference from the startof the voltage reduction to the start of the voltage return to thedriven level.

Light source 812 may, in various embodiments, be segmented (e.g., asfurther described below). In some embodiments, the backlight may besegmented into five independently addressable rows. For instance, lightsource 812 may be segmented into sections that may extend acrosshorizontal bands of the display. The LEDs of light source 802 may pulseat different times, which may be optimized for timing one segment'spulse separate from other segments. Further, a segmented light source802 may include segmented light guides that may help minimize row-to-rowcrosstalk.

In some embodiments, one or more components of LCD display 800 may beimplemented by a computer-readable storage medium, memory, or some othercomponent. A computer-readable storage medium may be some embodiments ofan article of manufacture that stores instructions that are executableby a processor. As an example, a computer-readable storage medium can beused to store instructions read by a program and used, directly orindirectly, to fabricate hardware for control circuitry 804, describedabove. For example, the instructions may outline one or more datastructures describing a behavioral-level or register-transfer level(RTL) description of the hardware functionality in a high-level designlanguage (HDL) such as Verilog or VHDL. The description may be read by asynthesis tool, which may synthesize the description to produce anetlist. The netlist may include a set of gates (e.g., defined in asynthesis library), which represent the functionality of controlcircuitry 804. The netlist may then be placed and routed to produce adata set describing geometric shapes to be applied to masks. The masksmay then be used in various semiconductor fabrication steps to produce asemiconductor circuit or circuits corresponding to control circuitry804.

Segmented Backlight for Higher Dynamic Contrast

In some existing implementations, dynamic contrast is defined as amaximum luminance ratio achievable by a display on consecutive frames.In practice, dynamic contrast may be measured by switching a displaybetween a color level of 0 and a color level of 255 in consecutiveframes and measuring the ratio of the luminances of the bright and darkframes.

Higher dynamic contrast can be a critical requirement for many differentapplications of liquid crystal displays (LCDs). These applicationsinclude, but are not limited to, low motion blur in high frame ratemonitors and/or low cross-talk in time sequential stereoscopic displays.The dynamic contrast of the display may be limited by the slowtransition speed of the liquid crystal materials (e.g., as describedabove), especially in the transition from high to low voltage state.FIG. 9 illustrates a typical optical response of a liquid crystal cellunder consecutive switching between low voltage (low V) and high voltage(high V) states, according to existing implementations. Note that due tothe long transition time, a typical dynamic contrast would be expectedto be in the range of 50:1 or less with a continuous backlight.

One improvement that has been implemented in many high frame rate gamingmonitors is the use of pulsing backlight, e.g., the backlight may beturned on only when the liquid crystal has already approached the laterstage of the transition. The pulsing backlight therefore cansignificantly improve the dynamic contrast if there is a good timingoffset for the entire display. However, the time it takes to scan fromthe top row of pixels to the bottom row can be several milliseconds andno timing offset may be optimal for the entire screen. In other words,no matter the backlight is turned on, there will always be some regionsof the display that has the backlight turned on too early and/or toolate. Thus, a typical monitor will compromise top and bottom areas ofthe monitor for better dynamic contrast at the center area. In otherwords, the activation of the backlight will be optimized for betterdynamic contrast in the center of the monitor at the expense ofsub-optimal dynamic contrast in the top and bottom areas of the monitor.

Thus, to further improve the dynamic contrast, the next stage ofcustomization is segmented pulsing backlight. Essentially, a backlightis divided into several segments that can be controlled individually.Each segment is then chosen to have a timing offset to match with anoptimal timing offset for only the rows of pixels that it covers.Theoretically, the entire display panel can have optimal timing to gethigher dynamic contrast. However, light from a turning-on segment leaksto nearby segments and creates undesired luminance in those segmentswhen liquid crystal is not in the optimal state.

FIG. 10 illustrates a typical optical response for a segmented pulsingbacklight and a corresponding voltage level of an LCD, according toexisting implementations. As shown a main segment may be close tooptimal time for liquid crystal response, but its neighbors, both frombefore and after, are turning on at non-optimal times. In other words,even though the intensity of the neighbor leakage is smaller than themain pulse, if it is too far away from the optimal timing and thecontribution to contrast drop can be substantial. Thus, a small leakageat the second or third neighbor can be problematic: the liquid crystalis already transitioning into the next state. Therefore, to achievehigher dynamic contrast, a reduction in light leakage between differentsegments of the backlight is needed.

Embodiments described herein provide systems, techniques, and methodsfor reducing light leakage between non-adjacent segments of a segmentedbacklight. In some embodiments, preventing light leakage to second andfurther neighbors (e.g., non-adjacent segments) may be more critical tohigher dynamic contrast than preventing light leakage to the firstnearest neighbors (e.g., adjacent segments). For example, FIG. 11illustrates an example of a segmented backlight, according to someembodiments. As shown each segment may have multiple cuts (e.g., notchesof any shape, depth, and/or length). For example, a segmented backlightsystem 1100 (which may include features as described above in referenceto FIG. 8), includes 3 pairs of LEDs 1114, each pair of LEDs 1114illuminating a corresponding panel 1112, for each segment 1110 a-e, andeach pair of side-lit-LEDs may have an associated cut (or notch) 1120that may be configured to reduce light transmittance. In someembodiments, the associated cut may be perpendicular to the associatedLEDs. In some embodiments, a portion of the cuts may be perpendicular(or substantially perpendicular) to the associated LEDs. In someembodiments, the cuts (or a portion (or subset) thereof) may be ofvariable length, depth, and/or width. In other words, the dimensions ofthe multiple cuts may vary in any of the three dimensions (length,width, depth). Further, in some embodiments, the cuts (or a portion (orsubset) thereof) may be non-linear in a direction perpendicular to theone or more sets of LEDs. In some embodiments, the cuts/notches, or asubset thereof, may be configured to be reflective (e.g., reflectsubstantially all light), some degree of opaque (e.g., absorb a portionof light, such as 10%, 20%, 30%, 40%, and so forth up to 99%) orblackened (e.g., darkened to absorb substantially all light).

For example, FIGS. 12A-C, 13A-C, 14A-C, and 15A-C illustrate variousexample embodiments of a cut/notch 1120. Note that 12A-C, 13A-C, 14A-C,and 15A-C are exemplary only, and other configurations and/or shapes ofcuts 1120 are envisioned.

FIGS. 12A-C illustrate one example of a cut 1120, according to someembodiments. As shown, the exemplary cut 1120 may have a variable depthand/or width (e.g., as illustrated by the triangular notch/cut). Asillustrated, the width at the surface of the cut may be constant anddecrease along the depth of the cut/notch 1120. In addition, the maximumdepth of the cut/notch 1120 may be constant. Further, the shape of thecut/notch 1120 (shown as a triangle, however, other geometric shapessuch as any quadrilateral and/or non continuous shapes, e.g., stairsteps, are also envisioned) may be constant.

As another example, FIGS. 13A-C illustrate an example cut 1120 in whichthe exemplary cut 1120 has a variable maximum depth as well as avariable depth and/or width. As illustrated, the width at the surface ofthe cut may be constant and decrease along the depth of the cut/notch1120. In addition, the maximum depth of the cut/notch 1120 may decreasefrom a first side of the cut/notch 1120 to a second side of thecut/notch 1120. Further, the shape of the cut/notch 1120 (shown as atriangle, however, other geometric shapes such as any quadrilateraland/or non continuous shapes, e.g., stair steps, are also envisioned)may be constant.

As a further example, FIGS. 14A-C illustrate an example cut 1120 in withthe exemplary cut 1120 has a variable surface width in addition to avariable depth and/or width. As illustrated, the width at the surface ofthe cut may decrease from a first side of the cut/notch 1120 to a secondside of the cut/notch 1120. Further, the width may decrease along thedepth of the cut/notch 1120. In addition, the maximum depth of thecut/notch 1120 may be constant. Further, the shape of the cut/notch 1120(shown as a triangle, however, other geometric shapes such as anyquadrilateral and/or non continuous shapes, e.g., stair steps, are alsoenvisioned) may be constant.

As yet a further example, FIGS. 15A-C illustrate an example cut 1120 inwhich the exemplary cut 1120 has a variable surface width in addition toa variable absolute depth as well as a variable depth and/or width. Asillustrated, the width at the surface of the cut may decrease from afirst side of the cut/notch 1120 to a second side of the cut/notch 1120.Further, the width may decrease along the depth of the cut/notch 1120.In addition, the maximum depth of the cut/notch 1120 may decrease from afirst side of the cut/notch 1120 to a second side of the cut/notch 1120.Further, the shape of the cut/notch 1120 (shown as a triangle, however,other geometric shapes such as any quadrilateral and/or non continuousshapes, e.g., stair steps, are also envisioned) may be constant.

Note that in some embodiments, LEDs within the same segment may stillhave the same timing control with respect to one another, but thecut/notch between the LEDs may create a barrier within the segment. Inother words, each segment may be configured as a light barrier toprevent light leakage to second and further neighbors. Unlike existingimplementations, in which focus has been on making more efficientbarriers between segments, embodiments described herein provided formore barriers within each segment. These additional barriers may not aidin preventing leakage to nearest neighbors, but may significantly reduceleakage to second and further neighbors. In some embodiments, the cuts(or notches) may be reflective (e.g., reflect all light), some degree ofopaque (e.g., absorb a portion of light, such as 10%, 20%, 30%, 40%, andso forth up to 99%) or blackened (e.g., darkened to absorb substantiallyall light) to further reduce light leakage to non-adjacent neighbors.

For example, suppose a segmented backlight system, such as system 1100described above, includes 3 pairs of LEDs for each segment, and each cut(or notch) reduces light transmittance by 50%. The relative luminance insegments 1110 d and 1110 e if all LEDs in segment 1110 c are on(illuminated) can be estimated by considering contribution from eachindividual LED pair 1114 and adding them up, e.g., as shown in the table1 below.

TABLE 1 Luminance Contributions Segment Segment Segment 1110c 1110d1110e Turn on LED 1 ½ ¼ ⅛ 1/16 1/32 1/64 1/128 1/256 1114 (c-1) Turn onLED ½ 1 ½ ¼ ⅛ 1/16 1/32 1/64 1/128 1114 (c-2) Turn on LED ¼ ½ 1 ½ ¼ ⅛1/16 1/32 1/64 1114 (c-3) Turn on all 1½ 49/32 49/256 1114c LEDS

Thus, the drop-off rate for nearest (adjacent) neighbor may be the ratioof luminance between segments 1110 c and 1110 d as shown in equation(1):

$\begin{matrix}{r_{1} = {\frac{L_{1110c}}{L_{1110d}} = {\frac{\frac{11}{2}}{\frac{49}{32}} = {\frac{176}{49} \approx {3.6\text{:}1}}}}} & (1)\end{matrix}$

Similarly, the drop-off rate for the next (non-adjacent) neighbor may bethe ratio of luminance between segments 1110 c and 1110 e as shown inequation (2):

$\begin{matrix}{r_{2} = {\frac{L_{1110c}}{L_{1110d}} = {\frac{\frac{11}{2}}{\frac{49}{256}} = {\frac{1408}{49} \approx {29\text{:}1}}}}} & (2)\end{matrix}$

Thus, a significant reduction of light leakage to non-adjacent neighborsmay be achieved.

Although the embodiments above have been described in considerabledetail, numerous variations and modifications will become apparent tothose skilled in the art once the above disclosure is fully appreciated.It is intended that the following claims be interpreted to embrace allsuch variations and modifications.

We claim:
 1. A segmented backlight, comprising: one or more segments;and one or more sets of light emitting diodes (LEDs) configured toilluminate the segmented backlight, wherein each set of LEDs illuminatesa corresponding segment of the one or more segments; wherein eachsegment of the one or more segments comprise: one or more notches,wherein each notch of the one or more notches is configured as a lightbarrier, wherein the light barrier reduces light leakage to non-adjacentsegments.
 2. The segmented backlight of claim 1, wherein at least onedimension of at least a portion of the one or more notches varies alongthe at least one dimension.
 3. The segmented backlight of claim 1,wherein at least two dimensions of at least a portion of the one or morenotches independently vary along each of the at least two dimensions. 4.The segmented backlight of claim 1, wherein at least a portion of theone or more notches are arranged to be perpendicular to the one or moresets of LEDs.
 5. The segmented backlight of claim 1, wherein at least aportion of the one or more notches are three-dimensional, having a widththat varies along the depth and length of the notch and a depth thatvaries along the width and length of the notch.
 6. The segmentedbacklight of claim 1, wherein at least a portion the one or more notchesare configured to be reflective.
 7. The segmented backlight of claim 1,wherein at least a portion the one or more notches are configured to beopaque.
 8. The segmented backlight of claim 1, wherein at least aportion the one or more notches are configured to be blackened.
 9. Thesegmented backlight of claim 1, wherein the segmented backlight iscomprised in a liquid crystal display (LCD).
 10. The segmented backlightof claim 9, wherein the LCD is comprised in a wireless station.
 11. Thesegmented backlight of claim 9, wherein the segmented backlight iscomprised in an LCD comprised in a three-dimensional stereoscopicdisplay system.
 12. The segmented backlight of claim 11, wherein thethree dimensional stereoscopic display system is a wireless station. 13.A liquid crystal display (LCD) system, comprising: an LCD panel; a lightsource configured to illuminate the LCD panel, wherein the light sourcecomprises: one or more segments, wherein each segment of the one or moresegments comprise one or more notches, wherein each notch of the one ormore notches is configured as a light barrier, wherein the light barrierreduces light leakage to non-adjacent segments; and one or more sets oflight emitting diodes (LEDs), wherein each set of LEDs illuminates acorresponding segment of the one or more segments; and control circuitryin communication with the light source and the LCD panel, wherein thecontrol circuitry is configured to provide a voltage signal to the oneor more sets of LEDs to illuminate the one or more segments of the lightsource.
 14. The LCD system of claim 13, wherein at least one dimensionof at least a portion of the one or more notches varies along the atleast one dimension.
 15. The LCD system of claim 13, wherein at leasttwo dimensions of at least a portion of the one or more notchesindependently vary along each of the at least two dimensions.
 16. TheLCD system of claim 13, wherein at least a portion of the one or morenotches are arranged to be perpendicular to the one or more sets ofLEDs.
 17. The LCD system of claim 13, wherein at least a portion the oneor more notches are configured to be reflective.
 18. The LCD system ofclaim 13, wherein at least a portion the one or more notches areconfigured to be opaque.
 19. The LCD system of claim 13, wherein atleast a portion the one or more notches are configured to be blackened.20. A wireless station, comprising: at least one antenna; at least oneradio, wherein the at least one radio is configured to perform wirelesscommunication via the at least one antenna using at least one radioaccess technology (RAT); a liquid crystal display system, comprising anLCD panel and a light source, wherein the light source is configured toilluminate the LCD panel, wherein the light source comprises a pluralityof segments, wherein at least one segment of the plurality of segmentscomprises at least one notch, wherein the at least one notch isconfigured to reduce light leakage to non-adjacent segments of theplurality of segments, wherein the at least one segment is illuminatedvia a set of light emitting diodes (LEDs); and one or more processorscoupled to the at least one radio and the LCD display system, whereinthe one or more processors are configured to cause the wireless stationto provide a voltage signal to the set of LEDs to illuminate the atleast one segment of the light source.